Deputy Prime Minister Nick Clegg said yesterday (11 December) that he was "bitterly disappointed" with the outcome of last week's summit, calling it "bad for Britain".
Clegg leads the pro-European Liberal Democrats, the junior partners in an uneasy alliance which has vowed to rule until the next election due in 2015.
Despite his disappointment over the government's stance on Europe, Clegg said it would be an "economic disaster" were the coalition to fall apart now when the economy is teetering on the edge of recession.
The Liberal Democrats have seen their poll ratings slide to little more than 10% since the 2010 election.
Cameron will address parliament at 15.30 GMT today to explain the outcome of the summit.
"Basically he'll reiterate what he's said over the last couple of days about why he did what he did and why he thought it was the right thing to do," said a spokesman for his Downing Street office.
"Britain is not a member of the euro. What they were debating about is how they are organised to make sure that the euro works," he said. "In terms of other types of policy, defence, all sorts of other policy, Britain will still be very much at the centre of things."
Many of the Conservative party's eurosceptics are expected to hail Cameron's veto, making the Liberal Democrats' position even more unsustainable.
In the meantime, the consequences of 8-9 December summit for the future of the European Union are far from clear.
Following Cameron's rejection of the summit deal, the remaining 26 EU countries have agreed a new "fiscal compact" on tighter budget and debt rules outside the community framework.
The role of institutions such as the Commission and the Parliament remains unclear in such an intergovernmental framework. The European Parliament is expected to hold a debate on the issue tomorrow (13 December).
The markets appear largely unimpressed following the EU summit. Moody's Investors Service said last week's agreement by European policymakers offered few new measures to resolve the region's debt crisis.
The communiqué reflects the continuing tension between euro-area leaders' recognition of the need to increase support for fiscally weaker countries and the significant opposition within stronger countries to doing so, Moody's noted.