It's been a very busy day, with lots of political reaction to Friday's terrorist attack in Sousse, Tunisia. Here's a round-up of the latest political developments:

- Home Secretary Theresa May described the attack as "terrible" and "appalling" and paid tribute to the victims and their families

- Mrs May chaired an emergency Cobra meeting at which a decision was made to boost the numbers of a team sent to Tunisia to look at protective security arrangements around tourist resorts. A medical liaison team has also been dispatched

- Shadow foreign secretary Hilary Benn said the Tunisia attack was "an unfolding human tragedy" and said the victims and the families must get the right support and assistance that they need

- UKIP leader Nigel Farage sounded a warning about Islamic State militants using the Mediterranean migrants boat crisis to "flood Europe with jihadists"

- The UKIP leader said he'd changed his position on surveillance powers and now believes levels should be increased

- Mr Farage also said he was qualified to lead the "no" campaign on the EU referendum, but hoped "somebody better than me comes along"

- Former Head of the Army Lord Dannatt said military support on the ground must be increased in the battle to fight Islamic State militants

- Ex-Labour home secretary Alan Johnson urged the government to press ahead with David Anderson's recommendations on surveillance powers, saying it was essential to give the security services the tools they need to do their job

- Labour's four leadership candidates took part in a hustings in Nottingham, where they answered questions from an audience and set out their pitch for the top job

- The European Central Bank is expected to end emergency lending to Greece's banks on Sunday, the BBC understands.

Image source, EPA

Some more on the Greek debt crisis. The country's finance minister, Yannis Varoufakis, has said that if the European Central Bank were to stop support for the Greek banking system that would mean that Europe had failed.

He told the BBC that Greece had done all it could to reach a settlement, and Europe was to blame for the lack of a solution to the crisis.

A Labour leadership hustings has been taking place in Nottingham, with the four candidates vying for the top job takings questions from an audience. In the closing minutes, they are asked to sum up why they want to lead the party:

- Jeremy Corbyn says he thought it would have been better to have delayed the leadership contest for a year to allow for a proper debate on the party's future. But we are where we are he says, before going on to make the case for the need to review the party's economic strategy to "confront the "neo-con agenda". Labour needs to reassess its international strategy, too, he adds.

- Yvette Cooper says Labour's election offering was too narrow and meant the party lost votes to the Conservatives, UKIP and the Greens. Labour needs to reach out to other parts of the country, she adds, and a leader who is "strong enough" to take on David Cameron - saying that she is the candidate to do that.

- Liz Kendall says Labour under Ed Miliband "lost touch" with too many parts of the country and lacked a positive vision for people's lives. The party needs to "turn the page and make a fresh start", she adds - saying she is the candidate to do that. Ms Kendall says she champions great businesses and sound public finances, and for responsibility "from top to bottom".

- Andy Burnham says he wants to win not just the contest but the election in 2020 "because I'm sick of losing". He says this can only be done by facing up to the "hard truth" that millions have lost their "emotional connection" with Labour. He will change that, he says, pledging to take Labour "out of Westminster".  His front bench will be "full of accents and diversity", he pledges, adding: "I'll give this party its pride back."

Some comments just in from Foreign Secretary Philip Hammond. He said: "We have to expect ... that the final analysis will show that a majority of those killed were British"

BBC News Channel

BBC correspondent Frankie McCamley says the Foreign Office updated its advice overnight, warning of more potential attacks in Tunisia. But they are not telling people not to travel, she adds. People are urged to get in touch with their travel operators, some of whom have travelled trips to Tunisia in wake of the attack.

"This is a terrible attack that has taken place," Mrs May says, adding that the Tunisian authorities are continuing to investigate. It is the most significant loss of British life in a terrorist attack since the London bombings in 2005, she adds.

Asked whether the Foreign Office has been slow to respond, Theresa May restates that they have been working around the clock, with a consular team dispatched to Sousse "quickly". She says it is a complex process to identify the victims and says it is essential to make sure they information they have is right.

The Cobra meeting has finished and Home Secretary Theresa May is outside the Cabinet Office making a statement. She says the Foreign Office is "working around the clock" with consular staff on the ground in Tunisia since the incident took place.

She says a medical liaison team has been dispatched to Sousse, as well as a small team to look at "protective security arrangements" around tourist resorts. The numbers of that team will be increased, she adds.

The UK's ambassador in Tunisia will also meet senior government figures there this afternoon as well, to emphasise the importance of "smooth liaison with the authorities" she adds.

Mrs May says the number of confirmed dead remains at 15 but that this is expected to continue to rise.

We mentioned earlier that Home Secretary Theresa May is chairing a meeting of the government's emergency Cobra committee following the terror attacks in Tunisia. We'll bring you lines of the statement as soon as we get it.

Asked again who should front the "no" campaign in favour of a British exit from the European Union, Mr Farage says:

On to the EU referendum, Nigel Farage is asked if he'd like to front the "no" campaign. He says he likes the idea floated by businessmen the other day of a broad-based group that doesn't include politicians to make the case for leaving the EU,  adding "let's see who emerges from that".

He goes on to criticise Tory eurosceptics for saying "wait and see" what David Cameron EU renegotiation will achieve, saying the PM's dream of treaty change  "fell" at the weekend's European Council summit.  He says he's not prepared to "sit and wait" for the outcome of the talk - and pledges that UKIP will "play our bit" in the campaign. 

Should we be taking the fight to Islamic State? Nigel Farage says that to send the British army to one country would achieve absolute nothing., If there was to be a military strategy against the "evil ideology" it would need to be done in conjunction with the different governments in the region and take place on a "broad canvas" with the acceptance it could take 20 years, he adds.

Nigel Farage says the UK's ability to control its borders is at "the heart" of the debate on the EU referendum. "This is a real threat," he says of jihadists exploiting the migrants boat crisis. The UKIP leader says he believes that every vehicle at Calais will have to be stopped and checked - or at the very least a "much higher percentage" than at present.

UKIP leader Nigel Farage says 160,000 migrants have reached Europe from the Mediterranean, and that the EU is now implementing a common asylum policy "which means that anyone from Africa can stay".

He raises concerns that terrorists are reaching Europe on the migrants boats, and will use it as an opportunity "to flood Europe with jihadists". The EU should follow Australia's lead and refuse to accept the Mediterranean boat migrants, he suggests.

Mr Farage goes on to accuse the UK government of "complacency", saying that not being a part of the asylum policy does not mean that migrants will not reach UK borders.

On surveillance powers - and David Anderson's report into this - Hilary Benn says the law needs to be updated. He adds: "We need to have an honest, grown up debate about how to balance privacy and security," he adds.

"We've got to win the battle for attitudes... for hearts and minds" says Lord Dannatt. He says there has to be a narrative coming out of mainstream mosques in Europe and for pressure to be applied to governments like Saudi Arabia and Qatar "not to be ambiguous about their approach to Islamist extremists". IS ideology is a "perversion" of Islam and needs to be "discredited", he adds.

Panellist Tim Marshall suggests that political parties have been inviting people into the country to have a platform in universities and mosques of extreme homophobia, anti-semitism and mysogyny - and it "has got to stop".

Hilary Benn agrees with the point put to him that military response aside, there is a "huge job" to be done to galvanise the Islamic world and Muslim population in this country to put forward a credible alternative narrative to that of Islamic State. He says the UK has a responsibility in this area, and stresses the need for each country to play its part.

"There is barely a part of the world that hasn't been touched by these types of attacks," says Hilary Benn. We need to take on this idea that you can kill innocent people.

Meanwhile, Lord Dannatt - former head of the Army - says "we're not doing enough right across the piece". IS wants to "cause chaos and exploit it", he says, as he urges more to be done on political, diplomatic and military grounds. Lord Dannatt says there should be more support for those fighting IS militants on the ground.