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Shadow foreign secretary Hilary Benn tells the same programme that it is "an unfolding human tragedy" in Sousse, and pays tribute to the victims and their families. What's most important today is making sure they get the right support and assistance, he adds.

Mr Benn says the attacks show there is a threat "everywhere". Asked if the West's response is inadequate, he says "we all need to do more".

Maajid Nawaz, founder of the Quilliam Foundation, says it is "especially significant" that the latest terror attacks have taken place during Ramadan after so-called Islamic State's "call to arms". "They see it as a month of war," he says of the militants.

Time now for the Sunday Politics. Joining Andrew Neil in the studio will be UKIP leader Nigel Farage, former head of the Army Richard Dannatt, and shadow foreign secretary Hilary Benn. We'll be bringing you all the key lines.

Returning to Theresa May's appearance on The Andrew Marr Show, she suggested that British officials were facing difficulty in identifying victims, because few were carrying anything with them.

The home secretary said those on the beach would not have had passports or other forms of identification with them and some victims were being moved between hospitals in the country.

Speaking to The Andrew Marr Show earlier, Virgin Group founder Sir Richard Branson said a British exit from the European Union (EU) would be "catastrophic"

He said Britons should be "proud" of being Europeans and remaining a member of the EU meant "talking from a position of strength".

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Former security adviser Lord West tells Pienaar's Politics:

Liam Fox stresses the need to be careful about "the danger of talking about the Muslim community as though it as a homogeneous community".

Sadiq Khan says all of Britain's communities need to have confidence in the police and the authorities in order to come forward to report any criminality. There is "a responsibility incumbent" on these authorities therefore to win that trust and confidence, he adds. Mr Khan adds that there needs to be "a more representative" police service. He says it is "encouraging" that the government "understands the importance" of having all communities on the same side.

Sadiq Khan, Labour's justice secretary, is the latest guest on Pienaar's Politics show. He's asked for his view on the home secretary's call this morning for Muslim communities to be alert to - and report - any signs of radicalisation. The Labour MP says her intentions are "right" and "noble".

Liam Fox says he supports the government on the need to "constantly review" what powers the security services need. "But it's got to be counter-balanced by better oversight," he says, including by judges and parliament. It's crucial how much the public buy in to the balance between liberty and security, the MP adds.

So-called Islamic State did not develop overnight, they are well funded and well structured, says Liam Fox. The West needs to ask itself whether it knew it was happeing "and turned a blind eye" and if it didn't know, "then why not?".

"But it's never to late," he says, as he underlines the need to defeat the ideology. He says that the collapse of the tourism industry in the region as a result of terror attacks would be dreadful.

Liam Fox argues that by giving more rights, especially to women, and by creating more economic prosperity in the region "you can diminish the reservoir" on which the terrorist thrive. States in the region can do more to deal with the so-called Islamic State, too, he adds.

But the Conservative MP cautions against "compromising our own position by taking short-term compromises" and working with Syrian President Bashar al-Assad, for example.

In wake of the terror attack, David Cameron has said "we will defeat them". Asked if this is possible and what victory looks like, Liam Fox says: "Peace is not the natural state of affairs, it is something we have had to construct very carefully and with a lot of dedication over a period of time."

He goes on to discuss the roots of Islamism, before saying: 

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Asked if the Tunisia beach attack was inevitable, former Conservative Defence Secretary Liam Fox says no it was not. He says you need to look at two things: the rise of Islamism and Islamic fundamentalism and "the reservoir of young people" who may be easily led down that path. "These are two very different battles," he adds.

A bit more from Alan Johnson's interview on The Andrew Marr Show earlier. The former home secretary called on 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.

Mr Johnson described Mr Anderson's report as "very effective" and said the Conservatives could no longer blame the coalition for not moving on with its implementation.

The Andrew Marr Show

Asked about reports that Boris Johnson will campaign for a "no" vote to exact more changes from the EU, Mrs May says she is approaching the negotiations "on the basis that we will be able to negotiate a positive package than can be put to people in the referendum". She says the reforms are of interest to other EU leaders, too.

"There will be bumps in the road," the home secretary adds. She tells the programme a key area for her is freedom of movement but she says she won't be setting out any red lines on this programme.