The Deputy Prime Minister Nick Clegg has refused to confirm whether he and his party will split from his Coalition colleagues and join Labour in voting for a "mansion tax", despite accusing the party of "blatant plagiarism" over the policy.
Ed Miliband has called on the Liberal Democrat leader to back the plans he has long championed in public in a Commons vote and oppose the Conservatives.
But while he has today attacked Tory rejection of the tax proposal, Mr Clegg told ITV News he would not yet stand with Labour on the issue because he has "no idea what we'll be voting on".
Mr Clegg said:
Neither Vince nor I know what will be put before us so we can't of course determine in advance how we would vote.
But of course the Liberal Democrats for a long time have been the leading advocate of greater fairness in tax.
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