A Devon MP is to oppose potential cuts at Devonport navy base while serving on a committee that is looking into the future of Britain's armed forces.
Devonport is the sole UK refitter for nuclear missile submarines
Plymouth Devonport MP Linda Gilroy (Lab) is among MPs on the House of Commons Defence Committee carrying out a new inquiry into provision.
The Ministry of Defence is reviewing cutting capacity and costs at Faslane, Devonport and Portsmouth bases.
Mrs Gilroy pledged to back Devonport while on the committee.
She said: "We think we can give very good value for money at Devonport."
The inquiry, entitled "UK Defence: Commitments and Resources", follows Tony Blair's call on 12 January for a national debate on future defence capabilities.
Mrs Gilroy said she would also remember hundreds of armed forces personnel from the south west who are serving in Afghanistan and Iraq.
Devonport, western Europe's largest naval shipyard, employs 4,800 people and is the UK's sole refitting base for Vanguard submarines, which provide the UK's strategic nuclear deterrent with Trident nuclear missiles.
The results of the Ministry of Defence review will be published next spring.