Nick Clegg accused Defence Secretary Philip Hammond of "jumping the gun" on Trident, as coalition tensions grow over the future generation of British nuclear-armed submarines.
The Deputy Prime Minister dismissed suggestions that an additional £350 million of funding announced for designing a replacement deterrent "made clear" the Government's commitment to maintaining the system.
Mr Clegg insisted the coalition agreement will not be "undermined or contradicted" and the Liberal Democrats' review into alternatives will continue.
Having seen the papers this morning, I think some people are jumping the gun on this Trident decision.
The coalition agreement is crystal clear - it will not be changed, it will not be undermined, it will not be contradicted.
The final decision on Trident replacement will not be taken until 2016, however much other people may not like it that way.
More top news
The majority of parents forbid their child to walk to school because they worry for their safety, an exclusive poll has found.
Singer James Blunt has called his best-selling hit You're Beautiful "annoying".
Owners could be fined £20,000, forced to take their dog to obedience classes or have them neutered if the public complain.