That's it for the politics live page for tonight. Here's a recap of the top stories as Sunday draws to a close:

• David Cameron will pledge tomorrow to "renew a sense of fairness" in society as he addresses Conservative backbenchers for the first time since the election
• Iain Duncan Smith will stay as work and pensions secretary in Mr Cameron's new cabinet. Earlier, it was announced Michael Gove will be justice secretary and Mark Harper chief whip

• Lord Mandelson warned earlier that Labour needs a profound rethink about its future

• Liz Kendall said she wants to replace Ed Miliband as Labour leader, while backbencher Dan Jarvis rules himself out of the race

• SNP leader Nicola Sturgeon called for new tax and welfare powers to be devolved to Scotland as a "priority"

• UKIP's only MP, Douglas Carswell, ruled himself out of the running to replace Nigel Farage as leader

Following his reappointment to the cabinet as work and pensions secretary, Iain Duncan Smith said: "I am delighted to have the opportunity to complete the vital welfare reforms that have already helped so many people back into work.

"The completion of Universal Credit will ensure work always pays, and will improve the incomes of those on low salaries."

Barnsley Central MP Dan Jarvis, who explains his decision not to stand for the Labour leadership in a column in the Times, external , also gives his take on Labour's election failure.

"It was a judgment on our failure to move out of the comfort zone of critiquing the Tories and instead set out a positive alternative," he says.

"The Labour Party has no divine right to expect the support of the British people. We have to earn it."

And he notes:

Iain Duncan Smith is to remain as work and pensions secretary in David Cameron's cabinet, No 10 has announced.

Baroness Stowell also retains her post as leader of the Lords, and is promoted to full member of the cabinet.

The Labour Party has described as "pathetic and without any foundation" claims made by George Galloway of "widespread malpractice" during the campaign for the Bradford West seat.

The Respect Party leader, who lost his seat to Labour's Naz Shah in a bitterly fought contest, said he was "in the process of compiling the information which will form part of our petition to have the result set aside". The claims relate to postal voting, he said.

But a Labour spokesman responded: "George Galloway should accept he was booted out by the people of Bradford West."

Chris Mason
Political Correspondent

"Dan Jarvis is very highly regarded within the Labour movement. A former solider who served in Afghanistan, he's seen as someone with plenty of ideas for Labour's future.

"However, he lost his wife to cancer, he has young children and he felt that attempting to bring them up while being leader of opposition was too much of juggling act."

Dan Jarvis, mooted as a potential successor to Ed Miliband as Labour leader, has ruled himself out of the running. The Barnsley Central MP cited family reasons for not standing in the leadership campaign.

You might have seen actor and singer Charlotte Church brandishing this placard and attacking the Conservatives at the anti-austerity rally in Cardiff yesterday.

Image source, Matthew Horwood/Wales News Service

Well, it's earned her a stern rebuke from the party's leader in Wales. Andrew RT Davies told BBC Wales: "It's champagne socialists standing shoulder-to-shoulder.

"To denigrate the electorate, who has just spoken, within 48 hours of the election, is slightly unfortunate and unbecoming."

Image source, AP

Former Respect MP George Galloway has tweeted, external that he's launched a legal challenge against the election result in Bradford West. He writes: "We've begun legal proceedings seeking to have result of the Bfd West election set aside. I cannot therefor discuss my own election for now."

Mr Galloway lost the seat by more than 10,000 votes. That was despite the Labour campaign facing setbacks including the resignation of its original candidate.

The Liberal Democrats say more than 5,000 people have signed up as members since their rout in Thursday's election.

Dr Fergal Monaghan, a data scientist at Adoreboard who led the study we referred to earlier (see 18:48 BST post), says social media played a critical role during the election.

Dr Monaghan adds: "Top-down blanket canvassing like leafleting has been replaced by bottom up canvassing where politicians must listen to an electorate of tech-savvy and often political sceptics."

During his brief interview with Channel 4 News earlier, Prime Minister David Cameron spoke about his plans for a new deal with the EU.

Image source, AP

SNP leader and Scottish First Minister Nicola Sturgeon was the most popular UK politician on Twitter during the election, according to a study. Data scientists Adoreboard said Ms Sturgeon was 14 points ahead of Prime Minister David Cameron. Mrs Sturgeon's Twitter handle received more than 163,000 mentions, 71% of them positive. The PM's Twitter handle had 145,405 mentions, 64% positive, the researchers said.