Michael Gove has claimed a Labour-SNP coalition would be a "Frankenstein administration" as senior Conservatives step up their attacks on Ed Miliband.

The Scottish-born Conservative chief whip warned a deal between Labour and any of Westminster's smaller parties would be comparable to Mary Shelley's scientist's most famous creation "stitched together (and) capable of causing great harm."

In a bid to tempt voters back to the Tories he added that the real choice in May's General Election was between two outcomes: "Either David Cameron will be Prime Minister or Ed Miliband."

Polls suggest that between them Labour and the Tories could poll the lowest share of the vote in recent history, as the electorate increasingly backs others including the SNP, Ukip and the Greens.

Pollsters also predict the UK could be heading for a second hung parliament, meaning neither of the two largest party would be able to form a majority government on their own.

In a bid to pull voters back to the Conservatives, Mr Gove significantly stepped up the rhetoric on what a Labour-led coalition would mean.

However, he made no mention of any possible Conservative-led coalition.

Many Tories hope the Democratic Unionist Party (DUP), who currently have eight MPs, could help them into government if they fall just a few seats short in May.

In warnings designed to scare voters south of the border, but which could have the opposite effect in Scotland, Mr Gove told an audience in London a Labour- SNP alliance would "have to impose policies on English voters designed explicitly to appease Scottish separatists."

He warned that it "might reduce spending on public services in England to insulate public services in Scotland.

"It might cancel infrastructure investment in England in order to subsidise investment in Scotland."

He also raised the prospect of former First Minister Alex Salmond, the frontrunner to win the Westminster seat of Gordon, becoming Deputy Prime Minister or even Chancellor.

Mr Gove said that a Labour government, whether ruling alone or propped up by any of the smaller parties, SNP, Plaid, Lib Democrats, Greens or any of the Northern Irish parties, "could not be relied on to keep public spending under control".

He added: "A Miliband-led administration reliant on the support of minority parties risks creating ... a Frankenstein administration - a stitched together creation capable of causing great harm."

Angus Robertson, the SNP Westminster leader said: 'Michael Gove is talking utter nonsense

"From a man who has been in a coalition that is responsible for a huge austerity programme - savage cuts - the Bedroom tax and billions more on Trident it is ridiculous language."

Mr Gove also hit out at the Liberal Democrats, accusing them of trying to take the credit for Conservative policies in government.

He said it was a "myth" that the Lib Dems had been more compassionate within the coalition and said that the "driving energy" for social progress had come from Conservative ministers.