The Faslane submarine base on the Clyde could end up as home port to Britain's planned £3.8bn aircraft carriers as well as the Trident nuclear deterrent squadron, under proposals being considered by naval chiefs.

Insiders say plans to scrap one of the Royal Navy's three remaining bases - Faslane, Portsmouth or Devonport - have now been abandoned in favour of efficiency savings of more than £30m a year at each site and a redistribution of warships.

Portsmouth, known as "Pompey" to generations of sailors back to Nelson's time, had been targeted for closure but is understood to have been saved from the Treasury axe because of its historic claim to be the spiritual home and headquarters of the Navy.

A final decision on the bases' future was expected this spring but has been postponed until autumn while the Ministry of Defence fights for extra cash in Whitehall's departmental spending review.

Naval sources say the go-ahead for construction of the two 65,000-tonne carriers will be made at the same time, triggering an internal battle over where they will be based when they enter service from around 2015.

One insider told The Herald: "Portsmouth is too restricted and the notoriously shallow channel to the naval base there would have to be dredged constantly to give clearance for ships of that displacement.

"Plymouth's Devonport base has similar problems and is a navigational nightmare.

"That leaves Faslane. Even at low tide, a 65,000-tonne warship has enough clearance to dock there in a superbly sheltered anchorage.

"The Clyde complex also has some leeway for accommodating the extra logistical back-up the carriers would need."

Faslane, with more than 6000 civilian and military employees and an annual operating budget of £270m, is already Scotland's single largest industrial employer. The alternatives to using one of the existing naval bases as the carriers' home port would be to establish a new, purpose-built facility with deep-water access or to re-open Rosyth in the Firth of Forth. The naval base there was closed in 1994 after more than 80 years as a major naval hub.

The first is deemed unlikely on cost grounds and the second, although attractive from the point of view of proven conditions needed for handling huge warships, would also be expensive and politically contentious.

It lies next to Prime Minister Gordon Brown's Kirkcaldy and Dunfermline East constituency.