Ms Sturgeon says Ms Grahame should almost certainly declare an interest, before saying she expects to pay a heavy price  for that attempt at "lightening the mood".

Ms Sturgeon says the ageing population presents a "significant challenge" and says that it is built into government plans. 

SNP MSP Christine Grahame asks what forward planning is in place to meet the demographic challenges of an ageing population - joking that she should perhaps declare a personal interest in the issue.

Tory MSP Miles Briggs asks if it is fair to double parking charges for NHS staff at Edinburgh Royal Infirmary.

Ms Sturgeon says she shares the concern and says it is not fair to staff or visitors to Edinburgh Royal Infirmary.

The first minister says free parking could not be introduced due to the hospital's PFI contract and says the health secretary will talk to NHS Lothian.

The Scottish Lib Dem leader says: "We must work together with our partners wherever they are in the world."

Mr Rennie says soft power like international aid must be used and stresses that similar attacks happen across the world.

Ms Sturgeon agrees and says other countries have incidents like the Westminster attack regularly.

The first minister says the importance of all countries working together on security is vitally important.

She says: "There are many, many things that unite us."

Ms Sturgeon says she feels very strongly the responsibility to do everything that can be done to protect the public.

The first minister says we must not allow terrorists to get what they want and a balance must be struck between public safety an freedom.

"The public must be kept safe to allow the public to get on with their own lives", she says.

Ms Sturgeon says she agrees "very strongly indeed" with Mr Rennie. 

The first minister says those of us who have never worked in Westminster can also relate with experiences of Holyrood and those who work to keep MSPs safe at the Scottish Parliament.

The first minister says these people are colleagues and friends. 

She says "it is understandable that people's instincts are to worry about security."

Scottish Lib Dem leader Willie Rennie says for four years he would walk over Westminster Bridge on his way to the House of Commons.

Mr Rennie says he would nod to the policeman on his way over.

He says he will not be able to walk that way again without thinking of yesterday's attack

The former Lib Dem MP highlights PC Keith Palmer, "the officer who stood to defend democracy but lost his life in the process".

Mr Rennie says: "I want to be free to walk that walk again" and says we must act based on intelligence not on fear.

The Scottish Parliament debate on whether to seek a second independence referendum is to resume next Tuesday.

The debate was suspended on Wednesday afternoon following the terror attack in London that has left four people dead.

MSPs had been due to vote on Nicola Sturgeon's plan to ask Westminster for permission to hold a referendum.

But presiding officer Ken Macintosh ruled it would have been inappropriate for the debate to continue.

Parliament officials met on Thursday morning and decided that the debate and vote would be rescheduled for 14:20 on Tuesday of next week.

• London attack - latest updates

Mr Harvie asks the first minister to reflect on the children watching these events.

The Scottish Green Party co-convener says these events could shape them.

He says he can barely imagine the brutal reality of the impact on children of yesterday's attack.

The first minister says young people have to contend with 24/7 news on social media.

She say this makes everything seem so much more acute and we have to be conscious of the impact of that.

However she says social media makes the world smaller and enhances communication.

The first minister says "we must stand shoulder to shoulder" with Muslim communities.

Ms Sturgeon says any anti-immigrant sentiment must be called out and the police have assured her they will do that.

Scottish Greens co-convener Patrick Harvie express deep concern for everyone affected by yesterday's horrific events.

Mr Harvie expresses praise for the emergency service and the late PC Keith Palmer.

He says we must all build empathy and solidarity.

Mr Harvie says there are those who are expressing racist and anti-Muslim comments in reaction to yesterday.

He says any far right threats must be tackled.

Ms Sturgeon says we must stand strong against anyone who would seek to use terrorism to divide communities.

Image source, PA

An MP died after she was shot and stabbed in a "horrific" assault in her constituency in January last year.

Jo Cox, Labour MP for Batley and Spen, was left bleeding on the ground after the attack in Birstall, West Yorkshire. A man was arrested nearby.

One eyewitness told the BBC they heard her attacker shout "put Britain first" at least twice beforehand.

Tributes flooded in  from politicians including David Cameron, Jeremy Corbyn and US Secretary of State John Kerry.

Mrs Cox's husband Brendan  said  she would want people "to unite to fight against the hatred that killed her."

Image source, PA

Ms Sturgeon says she agrees with Ms Dugdale "wholeheartedly".

She says many people will have thought about Jo Cox yesterday and she praises the dignity of her husband Brendan Cox.

The first minister says this is an opportunity to remember Jo Cox's values.

Scottish Labour leader Kezia Dugdale says in the days following the "brutal murder" of Jo Cox "we resolved that there is more that unites than divides us".

Ms Dugdale asks Ms Sturgeon if she agree that the important thing is solidarity.