Desperate activists rallying against the construction of a "morally unjustifiable" third runway at Heathrow have declared a hunger strike.

Tens of protesters are expected to gather outside the Labour Party headquarters in Westminster on Saturday (June 9) to voice their opposition of the expansion of Heathrow.

Vote No Heathrow campaigners are demanding the Labour Party impose the strongest possible three-line whip on their MPs, demanding they vote against expansion.

A Commons vote on expansion is expected in the coming weeks after the announcement on Tuesday (June 5) that the cabinet had approved Heathrow Expansion.

A spokesman for Vote No Heathrow told getwestlondon that at least a dozen hardcore campaigners will go on hunger strike until Labour whip their MPs against expansion.

Starting from around noon, they will be joined outside the Labour headquarters in Victoria Street by tens of other campaigners who will be foregoing food for the day.

The "extreme" action of a hunger strike is being taken after a protest on Monday to get a meeting with Jeremy Corbyn yielded no results.

"We will not stop standing with the Labour Party, urging them to follow their heart and values and vote in favour of people until the whip their vote," said the spokesman.

The event will consist of banners, music and poetry.

Richard Davis, 38, London, said: "People are really not aware that this big decision is happening - we are trying to raise awareness that there is a ‘make or break’ vote on Heathrow in Parliament this month.

An aeroplane takes off over the rooftops of nearby houses at Heathrow Airport in Harmondsworth

"People should know and people should contact their MPs to tell them to oppose expansion. Climate breakdown affects all of us, but many of the 90% who have never been on a plane are being impacted first and worst. Building a third runway is morally unjustifiable."

A vote must be held within 21 days of the publishing of the National Policy Statement on Aviation. If MPs vote against the policy, the airport expansion project would be scrapped.

If the project gets scrapped, Heathrow will be eligible to claw back any money they have spent on expansion, according to a "poison pill clause" in an agreement from 2016.

It is expected the Conservatives will apply a three-line whip on their MPs, however Uxbridge and South Ruislip MP Boris Johnson is likely to dissent. Under Parliamentary convention, a cabinet minister must resign before opposing the government's three line whips in a Commons vote.