Plans to use an RAF base for a US ballistic missile defence system were sneaked out by ministers and should be debated in Parliament, MPs have said.
The Foreign Affairs Select Committee criticised the way plans were announced as MPs left Westminster for the summer.
The RAF base at Menwith Hill in North Yorkshire will host a tracking system linked to US satellites and interceptor missiles based outside the UK.
Committee chairman Mike Gapes MP accused ministers of evading debate.
"We regret the manner and timing of the announcement. And there's a resulting lack of parliamentary debate on the issue," said Mr Gapes.
"And our job as a select committee regardless of which government it is at any time is to hold the government to account and to scrutinise its behaviour and we are not happy with the way they have dealt with this issue."
The Ministry of Defence says there was "no intention" to bury the plans.
'Lack of debate'
On 25 July, Defence Secretary Des Browne revealed in a written statement that he had approved the US request to use the base for the ballistic missile defence (BMD) system.
But, in a report, the Foreign Affairs Select Committee has criticised the "manner and timing" of the announcement and "the resulting lack of Parliamentary debate" on the issue.
The committee of MPs went on to demand to know the exact date approval for the plans had been given to the US.
"We recommend that the government inform us of the date on which it received the formal proposal from the US to include Menwith Hill in the BMD system," its report said.
"We recommend that there should be a full parliamentary debate on these proposals."
Anti-nuclear campaigners CND also criticised the announcement, calling it "outrageous" and saying it was made with "total contempt for democracy and consultation".
Arms race hint
Washington says the aim of the anti-ballistic missile system is to confront the future threat of incoming missiles from what it calls "rogue states" such as Iran or North Korea.
But Russia has objected to the plans, believing the system is aimed at its own arsenal.
President Putin has even hinted at a renewed arms race and a revival of the Cold War.
In their report the MPs also warn of Russia's renewed strength on the world stage, fuelled by high oil revenues.
Liberal Democrat leadership contender Nick Clegg said he was pleased that the "duplicitous publication" of the decision had been highlighted, adding that he believed the plans would not improve security.
"It is time for Britain to wake up to the damaging geo-strategic effects of this missile defence scheme and pull out of our deal with America.
"It will never be possible to construct a global system of governance to deal with external threats if powerful nations simply act unilaterally whenever it suits them."
'Good for UK'
The Ministry of Defence (MoD) has denied it buried the announcement of the missile defence plan.
A spokesman said the government's approach to missile defence had not changed and that in 2003, after receiving a request from the US to upgrade the missile-tracking radar at RAF Fylingdales in North Yorkshire, the government had given Parliament the chance to debate the issue.
He added that despite the changes at the Menwith base "being minor in nature", the government had made a written ministerial statement "to ensure that Parliament had full visibility on all elements of this issue".
"It was also announced via an MoD press release. There was absolutely no intention to 'bury' this announcement."
The defence secretary has insisted the system will be good for both UK and European security.
Speaking in July, he said it was "a building block to enhance our national and collective security".
Mr Browne said the work at RAF Menwith Hill would support the existing UK-US missile warning mission and enable satellite data to be passed into the new US missile defence system.