Image source, PA

Alex Salmond has said the SNP is preparing to shake Westminster "to its foundations" after the general election. With polls indicating a huge swing to the nationalists in Scotland, the former first minister said Labour would find it "very difficult" to refuse the party's support in the event of a hung parliament. He was speaking as extracts from The Dream Shall Never Die, his referendum diary looking back on the campaign for independence, were published in the Scottish Sun on Sunday, external.

Quick interview with Paddy Ashdown on Pieenaar's Politics... Lord Ashdown says the party has a "rising cohort of extremely talented women" who are the "brightest and the best".

Tweets, external: that handshake moment between Ed Balls and George Osborne was great telly #marr

More from Pienaar's Politics on 5 live: Ed Balls shoehorns in a comment on the TV debate he has just challenged George Osborne to on the Andrew Marr show. "Are we not going to talk about the TV debates John? " he asks the presenter. And then adds that he thought George Osborne initially agreed to the debate, but "by the end of the handshake there was constructive ambiguity I think".

"He wants to do something so extreme that in the end I don't think it can be done," is how Ed Balls describes George Osborne's plans for the Budget. On the subject of Trident he said he would ask the question of whether the UK's defence security could be achieved with "three or four boats". Currently there are four nuclear submarines within the UK's Trident operation, with one permanently at sea.

Shadow Chancellor Ed Balls is now on On BBC Radio 5 Live's Pienaar's Politics, attacking George Osborne's Budget, due on Wednesday. He says "it would be a great irony" if the chancellor decided to back off on his commitment to have a £23bn surplus by 2019. The Financial Times is predicting Mr Osborne could increase his surplus target to £30bn.

So will there be a head-to-head debate between George Osborne and Ed Balls? Here is what the two men said as they shook on it: George Osborne: "Well I'm happy to meet you in a debate." Ed Balls: "We should shake on it and go for it." GO: "Ed I'm not going to... we're going to see who else wants to be part of that. I've got a very effective chief secretary, who I think would also want to be part of that debate." EB: "If only David Cameron was up for a one-to-one debate like George but for some reason David Cameron is running scared."

Here's a bit more detail about when Ed Balls was asked about a potential SNP deal with Labour. Asked by Andrew Marr to say the words "I rule it out", Mr Balls replied: "Ed Miliband said it's nonsense. It's not part of our plans. You know Andrew, you've been covering politics for 30 years, parties, large parties at this stage say we're fighting for a majority and we are. I'm not going to get involved in speculation about post-election deals. We're fighting for a majority."

tweets:, external Balls outplayed Osborne on the Marr sofa with that handshake trick. #Marr

Tweets, external: Symmetrical Marr - Balls won't rule out SNP deal, Osborne won't rule out UKIP deal

and

Tweets, external: Stand by for an election campaign defined in part by politicians keeping their options open on alliances (& prob on cuts too)

Ed Balls challenges George Osborne to a head-to-head TV debate and gets him to shake on it. Mr Osborne says he wants Lib Dem Treasury Secretary Danny Alexander to be part of it.

tweets:, external George Osborne: "no giveaways, no gimmicks," on the budget, but appears to duck specific question on whether it'll be fiscally neutral #marr

George Osborne describes Nigel Farage's offer of a pact with the Tories as "just total nonsense". "Voting for Nigel Farage makes Ed Miliband the likely prime minister," he says and that would mean no EU referendum. He is pushed to categorically rule out a deal with UKIP. But, like Ed Balls on the SNP, he does not quite get there. He says Nigel Farage is "not a credible participant" in the election.

Creating stronger links with cities in the north is something Osborne says he wants to do. "[The] northern powerhouse is something we have got to build in the country," he says. He said "what is exciting at the moment is there are more jobs being created" in those cities. But he also said he wanted to "create greater transport links and invest in science and manufacturing".

George Osborne is sticking closely to his script - talking about his "long term plan" and saying Labour would create economic "chaos". He's not giving much away about any surprises he might be planning to announce on Wednesday.

"I have an economic plan which is breathing jobs into the country," Osborne says on The Marr Show. But asked about whether he agreed with the Institute for Fiscal Studies assumption that his planned cuts were "colossal". He said: "We still have to make difficult decisions... this country is still borrowing too much."

tweets:, external George Osborne: We still have to make difficult decisions...the plans we have set out are the plans we intend to follow through #marr

"No giveways no gimmicks, a Budget for the long term." That's how George Osborne's sums up Wednesday's Budget.