The cash-strapped Royal Navy has a £100,000-a-year rear-admiral for nearly every one of the 25 destroyers and frigates in the surface fleet, the Herald can reveal.

It also has 221 captains and 831 commanders for a frontline force which has shrunk under defence spending cutbacks.

The Navy now consists of the 25 destroyers and frigates, two ageing but available aircraft carriers with a third in mothballs, a helicopter carrier, two assault ships, four Trident missile submarines and nine nuclear-powered attack boats, eight mine countermeasures vessels, 17 small patrol and fishery protection boats, six survey and hydrographic vessels and 18 Royal Fleet Auxiliary ships manned by civilian crews.

It has already imposed a five-year promotion freeze for officers above the rank of lieutenant-commander to save money and clear some of the log-jam in senior ranks by natural wastage.

Manpower is down to 36,000, of whom more than 6000 are officers, and predicted to fall further to help underwrite the £3.8bn cost of two new aircraft carriers due in service by 2015.

Because of a shortage of cash, no redundancy terms are being offered to senior officers regarded as "surplus to requirement".

There are also contingency plans to second middle-ranking officers to defence industry posts to save on office overheads at the three UK naval bases at Faslane, Portsmouth and Devonport. One of these is likely to be closed in further cost-cutting. Portsmouth, spiritual home of the navy for almost three centuries, is being touted as the most probable victim.

The MoD said yesterday it was unfair to equate the numbers of senior officers with the number of warships, since many of the individuals were "performing essential roles in shore command, training, logistics, and joint-service posts".

Rear-admirals are on the same pay band as major-generals in the Army and RAF air vice-marshals.

Derek Twigg, junior defence minister, said 15 of the 25 rear-admirals on the active list were "in Royal Navy or Nato posts, with others in tri-service appointments".