The group have tabled an early day motion - a kind of parliamentary petition - expressing their concern about the National Missile Defence (NMD) plans.
The MPs include Clive Soley, chairman of the Parliamentary Labour Party as well as Liberal Democrat foreign affairs spokesman Menzies Campbell and SDLP leader John Hume.
The Conservatives are accusing Mr Blair of running scared of his own party on the issue.
Mr Blair has so far adopted a "wait and see approach" to Mr Bush's National Missile Defence programme, saying Britain cannot give a response until it sees the details.
Grave doubts
The MPs are pressing the government to follow the advice of the Commons Foreign Affairs Select Committee and "voice grave doubts about NMD in the UK".
The group is worried President Bush's plans will break the Anti-Ballistic Missile Treaty, which was a corner stone stablitity between the US and Soviet Union during the Cold War.
It is thought the defence system would involve using the early warning radar base at Fylingdales, North Yorkshire.
The Conservatives have already voiced their support for the plans, saying the UK should work with America on the issue.
Iain Duncan Smith, the shadow defence secretary and Tory leadership candidate, said the Commons motion showed a revolt in the Labour ranks over NMD.
He claimed Mr Blair was "running scared of his party".
"Labour's CND heart is beating strong," he continued in a reference to the party's support for unilateral nuclear disarmament in the 1980s.
"The missile threat from rogue states is growing. This motion shows the Labour party cannot be trusted with Britain's defence.
"Britain should be supporting the US with its plans to build a missile defence system that will protect not just the US, but also Britain and other European allies."
Clear policy
A spokesman for the Ministry of Defence said the government's policy remained clear.
It had received no approach on using MoD sites for an American missile defence.
If and when the US made such a request, the government would consider the details.