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Lib Dem cabinet minister Danny Alexander has weighed in to the growing coalition row over Europe.

In an article for The Independent, he accused senior Conservatives of threatening the economic recovery by "flirting" with an EU exit.

The chief secretary to the treasury warned jobs could be put at risk if the Tories kept up their rhetoric.

It comes after his Lib Dem colleague Vince Cable compared the Tory stance on immigration to Enoch Powell's.

Mr Alexander warned that Conservative anti-EU sentiment in the run up to May's European Parliament elections would send a "shiver of doubt" through the boardrooms of companies considering investing in the UK.

"The fact that some senior Conservatives are arguing that Britain should vote to leave the EU is already unsettling investors and threatening jobs and growth.

"Further pandering to anti-Europeans would be bad for the British economy."

'Too quiet'

Mr Alexander, who was a leading figure in the campaign for Britain to join the euro before becoming an MP, said the Lib Dems would be the only party campaigning in the elections on an "unambiguously pro-European message".

Vince Cable's a bit like an old uncle at Christmas - slightly rude, does not always make sense, but he is part of the extended family so you live with it Grant Shapps, Conservative chairman

He said the party - which fears another drubbing in May's polls, which are being held on the same day as local elections - would campaign on the threat to British jobs if the country votes to leave the EU in David Cameron's promised referendum in 2017.

Citing research by academics at South Bank University which estimate 3.5 million jobs depend on exports to the EU, he said: "Pro-Europeans in Britain have been too quiet for too long. Next year is an opportunity to make our argument heard, and the Lib Dems will make sure we take it."

On Sunday, Vince Cable angered Conservatives by comparing their stance on the end of working restrictions on migrants from Romania and Bulgaria to Enoch Powell's "rivers of blood" speech.

'Hopelessly split'

Enoch Powell's speech in 1968, with warnings about inter-racial violence in the UK, led to it being known as the "rivers of blood" speech. It prompted his sacking from the Conservative front bench the next day.

Conservative MP Nigel Mills said Mr Cable should stand down from the coalition government over his "ridiculous" comments, saying it would now be "very hard" for the business secretary "to sit around the cabinet table" with the people he had criticised.

Media playback is unsupported on your device Media caption Nigel Mills: Vince Cable's comments "ridiculously over the top"

Conservative chairman Grant Shapps told the Evening Standard: "Vince Cable's a bit like an old uncle at Christmas - slightly rude, does not always make sense, but he is part of the extended family so you live with it."

The issue of immigration has been high profile ahead of the ending of the last work restrictions in the UK for people from Bulgaria and Romania on 1 January.

The Conservative and Lib Dem coalition have announced restrictions on access to benefits - but Mr Cable opposes the idea of a general cap on EU migration to the UK, which Conservative Home Secretary Theresa May has been exploring.

Labour immigration spokesman David Hanson said: "The government are hopelessly split and increasingly acrimonious on their approach to the end of transitional controls for Bulgaria and Romania.

"Rather than come up with practical measures in a calm and measured way, they have descended into name-calling and panic. Once again the rhetoric fails to match the reality with this government on immigration."