Home Secretary Theresa May is due to set out plans to opt out of a raft of EU police and justice measures in a move likely to stoke coalition tensions.
Mrs May will use a Commons statement to confirm plans to exercise a treaty right to withdraw from 130 cross-border agreements including the European arrest warrant.
The announcement will delight eurosceptic Tory backbenchers and comes as the attitude towards the EU among Conservatives in the Cabinet is hardening.
However, the Liberal Democrats insist an agreement within the coalition is not "even close" and are warning about the risk to public safety.
Under the opt out, Britain would withdraw from a block of home affairs measures and could then pick and choose which elements it wants to re-adopt.
The arrest warrant is a particular flashpoint, with Tories arguing that it has led to British citizens facing unfair trials abroad but the Lib Dems highlighting its role in returning suspects.
A senior Lib Dem source said Mrs May had no authority to go beyond the Government's stated position of being "minded" to use the opt-out while detailed talks continue.
All 130 elements had to be gone through "one by one", the source said.
Prime Minister David Cameron said last month that Britain "will be exercising the opt-out" but Deputy Prime Minister Nick Clegg made clear nothing had yet been decided.
Monday's announcement follows reports that a string of Tory Cabinet members want the UK to threaten to pull out of the EU altogether unless important powers are returned.
Education Secretary Michael Gove, Work and Pensions Secretary Iain Duncan Smith and Justice Secretary Chris Grayling are said to be among those pushing for a tougher stance.
Defence Secretary Philip Hammond said at the weekend that Mr Gove's position reflected a wider change of mood.
"The point that Michael is reflecting - and many of us feel - is that we are not satisfied with the current relationship," he said.
"The mood has changed...because for the first time in a decade, those of us who are uncomfortable with the way that relationship has developed see an opportunity to renegotiate it.
"It makes sense for Britain to be in the single market but to reset the relationship so we have a balance of competences which works for Britain and the British people."
Mr Cameron has suggested a referendum on Britain's involvement in Europe could be held after a new settlement is hammered out in the wake of the eurozone crisis.
