I have seen first hand how committed and dedicated they are and we must thank them for all they have achieved in Afghanistan, particularly in controlling the narcotics trade and ensuring the elections were as secure as possible.'

A small crowd gathered outside Wellington barracks to cheer on the troops as they marched down Birdcage Walk, through Parliament Square and through the Carriage Gate to the Royal Marines Band

One young boy waved a union jack while others including tourists from Germany, the U.S. and Japan clapped and cheered.

Lance Corporal Frank Wyatt, 25, from Oxford, said the support made a difference.

He said: 'People need to appreciate what we're doing and the more they know about it the better.'

The demonstrators maintain a permanent presence in Parliament Square to protest the wars in Iraq and Afghanistan

Medical Assistant Roxanne Starsmeare, 23, from Taunton in Somerset, had just completed her first six-month tour of Afghanistan.

She said: 'For the last three months I was one of the front-line medics and treated everything from cut knees to troops who had been seriously injured, of which there were unfortunately a lot.

'It was hard work but I learned a lot and made some good friends. I think people are increasingly appreciating what we do an it's a real boost to know the country is behind you.'

Onlooker Sterling Lacey, 73, a retired teacher, said: 'It's the last we can do to show our gratitude for all they've been through.'

Last weekend some 30,000 people turned out to show support for the troops on Armed Forces Day. 3 Commando will be holding a day of remembrance for fallen colleagues in Exeter on Saturday, where they are based, and some 1,000 personnel from the Brigade are expected to attend.

The five who shouted abuse are protestors who maintain a constant presence in Parliament Square to demonstrate against the wars in Iraq and Afghanistan.

Scotland Yard said there were no arrests.

NF Comment: The NF is opposed to the no-win wars in both Iraq and Afghanistan and believes that our soldiers should be brought home. British troop should ONLY fight for British interests. However this does not give the right for usually Islamic extremists to jeer and abuse our heroic returning troops. WELCOME HOME TO THE MARINES!