The Government has been warned against scrapping the Royal Navy’s amphibious taskforce under plans that could see Plymouth’s historic naval base stripped to the bone.

Sources have indicated that the Ministry of Defence (MoD) is to sacrifice the three landing ships based at Devonport Naval Base to fund and build a new generation of aircraft carriers.

With Devonport poised to lose its status as the base port for nuclear submarines and frigates, taking HMS Ocean, HMS Albion and HMS Bulwark out of the region would leave the maritime city with a skeleton flotilla. It would also raise questions over the future role of the South West’s Royal Marine units.

The amphibious unit — which was central to the operation that liberated the Falkland Islands in 1982 — is the latest facet of the MoD subject to speculation ahead of the department unveiling its first review of defence and security spending in October.

The loss of the amphibious fleet, and hundreds of military and civilian posts, would be economically devastating for the Westcountry and undermine the region’s forces reputation.

South West Devon MP Gary Streeter compared scrapping landing ships to Dr Beeching dropping the axe on railways in the 1960s – a move many later regretted.

Proponents argue the amphibious taskforce, which put troops ashore, is not suitable for modern conflicts such as Iraq and Afghanistan – as underlined by the ships undergoing lengthy refits in recent months.

But commentators point out that threats to national security are constantly changing, and selling off the fleet would leave the Armed Forces vulnerable.

Mike Critchley, editor of Liskeard-based Warship World, conceded that while “everything is being considered”, abandoning a commitment to amphibious assaults smacked of short-term thinking.

He said: “You can train a rifleman very quickly but to build an amphibious ship, pencil in ten years.

“So even if just to maintain the infrastructure, we should not scrap the ships. Even if you put one of the ships in a corner in Plymouth – in care and maintenance or whatever – at least you have something that is around in years to come. Something we haven’t sold to a country on the other side of the world.”

Reports also suggest that Britain could be forced to “borrow” American warplanes for its new aircraft carriers as the Armed Forces’ core capabilities are eroded by budget cuts.

The country could also turn to America for surveillance aircraft if plans to buy new RAF spy planes are scrapped.

Dr Liam Fox, the Defence Secretary, has said instead of “salami-slicing”, where pain is shared equally across the department, the cuts must be allocated strategically.

Defence sources have suggested this will result in the forces giving up entire capabilities, such as aerial surveillance and amphibious landing.

Britain would have to rely on allies until the defence budget recovered, when these operations could be resumed, the thinking runs.

Defence cuts could also have serious implications for the Navy’s two new Queen Elizabeth Class aircraft carriers, which will cost £5 billion and are due to enter service in 2014 and 2016.

To help fund the carriers, Navy chiefs could give up the service’s amphibious task force of landing ships and commandos.

The Daily Mail and the Daily Telegraph both reported a Whitehall source saying: “It comes down to a choice between carrier strike capability and amphibious landing, and they’re not going to give up the carriers.”

In such circumstances, Plymouth’s once proud naval flotilla would be a shadow of its former self.

It was announced last year that three of Plymouth’s seven Trafalgar-class nuclear-powered submarines will be transferred to Faslane, Scotland, by 2017.

By then, the other four N-subs will have been decommissioned.

Four Type 22 frigates currently based at Devonport will remain in the Westcountry until the end of their service between 2019 and 2022.

All that would be left in Plymouth would be five survey vessels.

Mr Streeter said: “What I fear is going down the Beeching route with the railways - that we make cuts we later regret. I would be very much against the amphibious fleet going.

I consider it to be one of the things we need in the future, and it would be very serious for Plymouth, as the home of the amphibious fleet.

“We must be careful not to be thinking short-term.”

Mr Critchley said there were many other areas ripe for cuts before turning to the amphibious forces.

He said: “The RAF does not do anything that the Army, Royal Navy and an airline couldn’t do.” It wouldn’t mean RAF guys disappearing — they would just wear different uniforms.

“But you would get rid of the massive bureaucracy.”

An MoD spokesman said: “The future configuration of our Armed Forces will be based on the findings of the Strategic Defence and Security Review, which is under way.

“Final decisions will depend on the outcome of the SDSR and discussions with the service chiefs. Until the review concludes, speculation about its conclusion is entirely unfounded.”