Royal Marines set to lose 200 positions amid funding cuts
Admiral Sir Phillip Jones, the First Sea Lord said the cut is the Navy's attempt to “meet the challenges of the dangerous and uncertain world”.
However, it has emerged the men will be transferred to the Royal Navy so they can staff their new, huge warships.
Royal Navy photo competition winners 2016 Tue, June 7, 2016
Breathtaking images issued by the Ministry of Defence of the Peregrine Trophy awards 2016 Will Haigh won Royal Navy Photographer of the Year 2016 Simmo Simpson won Best Maritime Image Award Jamie Weller won Royal Navy Amateur Maritime Image Award Joel Rouse won People's Choice Award
PA 1 of 11
Royal Navy photo competition winners 2016
Admiral Jones said he knew how vital the marines were as "the UK's premier high readiness contingency force”.
But the Admiral added: "I also know we must adapt to meet the challenges of a dangerous and uncertain world.
"The Government is investing in a new generation of ships, submarines and aircraft.
"As we introduce these capabilities into service, we must ensure we have the right mix of skills across each of the Navy's fighting arms to optimise how we use them, and the Commandant General and I have sought to find the right balance between sailors and marines in responding to this challenge."
But, a Whitehall spending watchdog warned that the force has been facing a staffing crisis ahead of the completion of the two new aircraft carriers, HMS Queen Elizabeth.
The National Audit Office said the shortage of engineers, intelligence personnel and war-fighting specialists in the Navy and RAF air crew could delay the deployment of the carriers.
Last week, a former Falklands commander begged the Royal Navy to avoid making the Marine cuts because it will make Britain look “uninterested” in defending their interests.
Major-General Julian Thompson, who commanded 3 Commando Brigade in the Falklands, warned Britain will not be able to defend Gibraltar if the cuts are implemented.
Get Quotes on Home Insurance
Major-General Julian Thompson said Britain will not be able to defend Gibraltar with cuts to Marines
General Julian said another “Falklands-style operation” will not be able to go ahead if the fighting strength of the infantry force is cut.
Admiral Jones said the Royal Marines "is vital to Britain's defence in the years ahead as they have been for the past 350 years".
He insisted the Marines help the Navy "conduct sophisticated operations from the sea, at a variety of scales and against a range of threats, using our new aircraft carriers as a base, to leading the Service's development of information warfare”.