By Caroline Wyatt
Defence correspondent, BBC News
The Conservatives claim the "military covenant" is broken
The Conservative defence team has been very careful to steer clear of any outright spending commitments at this stage, so far avoiding promises of any extra cash for Britain's armed forces.
But David Cameron has spoken of defence as one area were extra spending will be "essential".
The Conservatives' main fear is the state in which they may find the defence budget - when and if they gain access to the books - or the level of "unpleasant, unpaid bills", as the shadow defence secretary Liam Fox put it in a recent newspaper interview.
It is clear that this year's MoD planning round has been particularly difficult, leaving many at the ministry in grim mood, with a "black hole" in the long-term defence budget estimated unofficially at anything from £1bn to several times that amount.
That makes any firm promises on major procurement projects or extra spending extremely risky for the Conservatives until the full extent of the shortfall is known.
And that is why one of the party's key plans for defence, should it come to power, would be a comprehensive strategic review, in a fresh attempt to match Britain's military commitments to its resources.
Army 'too small'
The last such review came under Labour in 1998, and the current demands made on Britain's armed forces on operations far outstrip the defence planning assumptions made a decade ago - one reason the defence budget is so overstretched, as well as the troops themselves.
The Tories say they will streamline procurement and review all major capital projects.
However, it is believed that Mr Fox is committed to keeping three of the most expensive current defence equipment programmes: Britain's two aircraft carriers, the "future rapid effects system" (a new generation of armoured vehicles for the Army) and the replacement for Britain's nuclear deterrent.
The Conservatives also want to enlarge the British Army, saying that it is too small for its current commitments.
The party would pay for this by reducing the number of civilian MoD staff.
TORY DEFENCE POLICY
Carry out strategic defence review
Look after armed forces "better"
Make changes to equipment procurement
The Tories have also said they want to see the restoration of three infantry battalions abolished by Labour, although that might prove harder to achieve in practice.
There are worries among some former military chiefs that a Conservative government might not be any more generous on defence spending than the current administration.
One of the main planks of Conservative defence policy is likely to be a promise to look after those in the armed forces better. The focus will be on improving retention as well as on recruitment.
To that end, the Conservatives have set up a Military Covenant Commission, headed by author Frederick Forsyth, to look at how to provide better care for service personnel and their families.
Among the commission's recommendations in a recent interim report, which could form some part of a future Tory government's defence policy, was a scheme for preferential treatment on the NHS for the armed forces.
It also proposed extra school funding for the children of serving personnel, who often have to move between postings within the UK and abroad.
The commission also claimed that the military covenant had largely broken down, after 11 years of Labour government and tough operations in Iraq and Afghanistan.
Falklands veteran Simon Weston has advised the Tories
On the defence budget, the Conservatives are keen to see if any lessons can be learned for procurement from the current use of "urgent operational requirements", or UORs.
These have enabled the forces to circumvent MoD bureaucracy to order equipment needed urgently in theatre.
However, the current use of UORs may come with a sting in the tail for any future government, as the Treasury could seek to claw back some of the £3.5bn it has paid out from its reserves to fund these acquisitions.
There are no Conservative plans to reopen the military specialist hospitals and other facilities closed under previous Tory governments.
However, the party wants to see a dedicated military ward at Selly Oak Hospital in Birmingham, exclusively for use by the armed forces.
New procurement criteria for defence equipment would include capability, affordability, adaptability, interoperability and - crucially - exportability, with a promise to restore the Defence Export Services Organisation, axed last year by the government.
It is also clear that the Conservative defence team are no fans of the European Defence Agency, which Brussels wants to co-ordinate EU defence spending.
Many Tories see as it a direct challenge to the primacy of Nato, and as a wasteful duplication of resources.
Nor do they agree with closer EU defence integration, opposing the defence aspects of the Lisbon treaty.