David Cameron will today issue a rallying cry to Lib Dem and Ukip voters as fears grow that Britain is heading for weeks or months of political paralysis in a hung Parliament.

The Prime Minister says he wakes in the night worrying about the country ‘falling into the wrong hands’ after Thursday’s election.

Speaking at a rally today, the Tory leader will urge backers of smaller parties to switch to the Conservatives – warning of their ‘inescapable choice’ between him or Ed Miliband.

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David Cameron hit the campaign trail in Addingham near Ilkley today, where he helped 7-year-old Amelie Bone sit on his shoulders to watch the Tour de Yorkshire cycle race

Mr Cameron was watching the cycling race as the race for Number 10 remains as close as ever

David Cameron today issued a direct appeal to Lib Dem and Ukip voters to lend their votes to the Conservatives in a bid to stop Labour and the SNP. He also appeared at a Hindu temple (right) on Saturday

He will put Tory plans to cut taxes for 30 million working people, by raising the income tax threshold to £12,500 and the 40p threshold to £50,000, at the heart of his campaign.

On a visit to Yorkshire and Warwickshire yesterday, he directly addressed Lib Dem or Ukip voters, urging them to ‘stop and think’ about the dangers of letting in a Labour government propped up by the SNP.

Mr Cameron plans to seize power if the Tories emerge as the largest party but again fall short of an outright majority – but faces a bitter power struggle. Senior Labour figures indicated they will seek to form a minority government even if their party finishes second. With the backing of as many as 50 Scottish Nationalist MPs, they could still enter Number 10.

Shadow Chancellor Ed Balls said yesterday: ‘David Cameron is trying to claim he can cling on to Downing Street, regardless of the constitutional rules or historical precedent. It’s nonsense.’

In a speech to activists at Ambleside Sports Club in Nuneaton, Mr Cameron insisted he is the 'only option' for avoiding a 'calamitous' and 'chilling' tie-up between Ed Miliband and the SNP

Clutching a copy of the 'there is no money left' note left by the last Labour government, Mr Cameron urged people to use the Bank Holiday weekend to 'stop and think' about the danger they face if Ed Miliband is forced to rely on Scottish Nationalists

It would be the first time since 1924 that a second-placed party has formed a government. Conservative ministers say voters would question the legitimacy of such an administration.

STEVE COOGAN BACKS MILIBAND Comedian Steve Coogan has joined other celebrities in backing Labour. In a party election broadcast the actor, 49, endorsed Ed Miliband, saying the Conservatives only want to help their ‘rich friends’. The multimillionaire, who championed state control of the Press after unflattering stories about his personal life, said he was inspired by his father’s values of ‘hard work, honesty and decency’. Comics Jo Brand and Paul O’Grady have also backed the party. Advertisement

The row suggests Britain could be facing a hung parliament in which no stable government can be formed – heralding economic turmoil and a long period of political uncertainty.

Tory sources say they expect to win at least 290 seats, giving Mr Cameron the chance to declare his intention to govern and daring Labour and the SNP to stop him by striking a formal deal.

Even without a formal pact, Labour and the SNP are expected to join forces to try to vote down the first Queen’s Speech – the legislative programme – of a minority Conservative government.

Labour MP Jonathan Reynolds, an ally of Mr Miliband, said: ‘Would the Queen read out a Queen’s Speech she knows doesn’t have support of the Commons? Personally I think not.’

Mr Miliband’s inner circle is said to have discussed how to keep him in place, believing a Tory-led coalition with a smaller majority than 2010 would be inherently unstable. They argue Labour needs to be ready for a second general election within months.

CITY FEARING NO CLEAR WINNER City investors have warned of chaos if the election sparks political paralysis. Market jitters could begin this week over the prospect of no clear winner emerging. There are fears that, in the event of a dead heat, the possibility of a lengthy period without a stable government could spook foreign investors, who may then pull out of the FTSE 100. Commerzbank economist Peter Dixon said some investors could withdraw from UK stock markets in the event of prolonged coalition negotiations. Advertisement

Lib Dem leader Nick Clegg indicated yesterday that the largest party had the right to seek to govern first, suggesting he could agree to Mr Cameron’s proposed EU referendum in exchange for more spending on schools and smaller welfare cuts.

But he told the BBC’s Andrew Marr programme there was a ‘wariness’ in his party about the idea of entering coalition again. Lib Dem Chief Secretary to the Treasury Danny Alexander confirmed that the Lib Dems would seek to work with whichever party had more seats.

Mr Cameron will say today: ‘By Friday you’ll either have Ed Miliband or me as your Prime Minister. It’s that simple, an inescapable choice: me leading a strong and stable Government, or with him: the chaos of being held to ransom by the SNP.

‘It’s that’s close. The risks are real and present. If Labour wins with the SNP’s help, Britain and its economic recovery will grind to a halt. The SNP will hold the Government to ransom every time there is a vote in the House of Commons – demanding more borrowing and higher taxes to pay for more welfare.

With a hung parliament the likely election result, Political Editor JAMES CHAPMAN looks at what will happen next...

Bird vote: Nick Clegg in Newhaven, East Sussex

What do the polls suggest the outcome of the election will be?

They suggest a slight shift to the Conservatives in recent days, but unless that dramatically gathers pace before Thursday, the UK is heading for another hung Parliament – the first time there would have been two in succession since 1910.

The Tories are only 23 seats below a Commons majority, but need to be much further ahead to hope to secure them, while Labour’s chances of a majority appear to have evaporated thanks to the rise of the SNP, set to deprive them of 30 or more seats.

Didn’t the Tories and the Lib Dems sort out a stable government pretty quickly in 2010?

Yes, in just five days. But the arithmetic clearly pointed to that, with the Tories well ahead.

This time, polls suggest Britain could have an ‘ultra-hung’ Parliament, where the two main parties are much closer.

Fears are growing that no stable government could emerge from this, with loose, multi-party tie-ups the only way any prime minister could get legislation through Parliament.

Wouldn’t the leader of the largest party automatically be PM?

No, there is nothing in the constitution that says the largest party’s leader has to be PM.

David Cameron is said to be preparing to declare victory if he wins the most seats and votes. He could seek to negotiate another coalition with the Lib Dems, and possibly Northern Ireland’s Democratic Unionist Party too. But with the Lib Dems facing the loss of half their seats, this may not add up to the 326 needed for a majority.

MORE VOTE FRAUD IN TOWER HAMLETS Postal vote fraud appears to be still going on in the London borough whose ballot- rigging mayor was kicked out of office. Tower Hamlets, in East London, is at the centre of an investigation after postal votes were sent to a derelict block of flats. None of the people who supposedly applied for the votes lives there and at least one is dead. The trial of Lutfur Rahman, found guilty last month of stealing his election to mayor, exposed rife corruption in the borough. Advertisement

If Labour can reach that figure through a deal with the SNP it could seize power. So Labour could be wiped out in Scotland, lose in England, not stand in Northern Ireland, win only in Wales and Ed Miliband still become PM.

Wouldn’t such a government face big questions about its legitimacy?

In terms of public opinion, almost certainly. Despite historical precedent, Nick Clegg yesterday suggested the biggest party should have the right to seek to govern.

Polls suggest half of voters would not accept the second-placed party propped up by a smaller party as legitimate. The situation would be complicated further by the SNP’s involvement.

It would be unprecedented for a party led by someone outside the Westminster Parliament – Scotland’s First Minister Nicola Sturgeon – to hold such sway. And voters in England are likely to baulk at the prospect of MPs from Scotland, representing only around 4 per cent of the UK electorate, calling the shots.

If the Tories are the largest party, couldn’t Mr Cameron simply lead a minority government?

Yes, in theory. He remains Prime Minister in a hung Parliament and could attempt to introduce a Queen’s Speech – his proposed legislative programme – and dare other parties to vote it down. But the situation is complicated by the Fixed Term Parliaments Act, brought in by the Coalition.

Labour is said to be considering whether it could seek a judicial review of parts of the Act to try to force Mr Cameron out with an immediate ‘no confidence’ motion.

What does the Fixed Term Parliaments Act mean?

It has removed the right of a PM to call an election whenever they like, ensuring they take place every five years on a fixed timetable.

LABOUR DUCK SNP QUESTIONS Senior Labour figures yesterday dodged questions over what concessions Labour would give the SNP for Commons support. Ed Miliband has dismissed the possibility of a formal deal or coalition. But shadow home secretary Yvette Cooper refused ten times to rule out an issue-by-issue deal, while deputy Labour leader Harriet Harman ducked similar questions four times. Boris Johnson said Westminster faced an ‘Ajockalypse’ unless the Tories win, with polls pointing to the SNP taking dozens of seats. Advertisement

A ‘super-majority’ of two-thirds of MPs must vote for an election at another time – meaning both main parties would have to vote in favour.

Defeats on what were considered issues of confidence, such as Queen’s Speeches and Budgets, would previously have brought down a government but now do not. A specific motion of no confidence must be passed by a simple majority and other parties then have 14 days to seek to assemble an alternative government.