Runaway Labour leadership frontrunner Jeremy Corbyn once backed a House of Commons motion welcoming the 'inevitable' end of human life on earth in an asteroid strike, it emerged today.

The veteran socialist signed the controversial motion, attacking people as 'obscene, perverted, cruel, uncivilised and lethal', after it emerged MI5 were planning to use pigeons as flying bombs in combat.

Mr Corbyn is a long-term campaigner against 'pigeon prejudice' – and has insisted the birds are 'intelligent and gentle creatures' which are cleaner than cats and dogs.

Runaway Labour leadership frontrunner Jeremy Corbyn once backed a House of Commons motion welcoming the 'inevitable' end of human life on earth in an asteroid strike

In 1996, his love of the birds moved him to attack plans to try to remove them from city centres.

The Islington MP criticised plans to force them out of Trafalgar Square and urged people to see the birds as 'friends rather than enemies'.

Mr Corbyn's pigeon campaign emerges in a series of Early Day Motions which he has signed during his long career as an MP – having first been elected in 1983.

The rebellious backbencher, whose has never been a minister or held a shadow ministerial role, has backed a host of left-field causes including a ban on 'war toys' for boys, homeopathy in the NHS and a ban on working in hot weather.

In 2003 Mr Corbyn signed a motion attacking the 'lack of gratitude' for carrier pigeons during the Second World War.

It added: 'This House believes that humans represent the most obscene, perverted, cruel, uncivilised and lethal species ever to inhabit the planet and looks forward to the day when the inevitable asteroid slams into the earth and wipes them out thus giving nature the opportunity to start again.'

Mr Corbyn signed a controversial motion, attacking people as 'obscene, perverted, cruel, uncivilised and lethal', after it emerged MI5 were planning to use pigeons as flying bombs in combat

In 1996 Mr Corbyn criticised 'prejudice' towards the birds, adding: 'Pigeons are less likely to transmit disease to human beings than dogs or cats and acid rain is a greater threat to the fabric of buildings than pigeon droppings.'

In 1991 he campaigned for British Rail staff to be allowed to keep 'calming' beards after new rules proposed banning facial hair.

Mr Corbyn joined with 14 MPs to call for the rules to be scrapped.

He said: 'This House further believes that beards are healthy and create the sympathetic image necessary for staff dealing with deeply distressed passengers.'

In 1995 he called for a ban on adverts for 'war toys' for boys - like Action Man figures - where there is 'a connection between such toys and male violence'.

Former Downing Street spin chief Alastair Campbell has claimed Jeremy Corbyn is unelectable

He has also called for the legalisation the possession of cannabis, dismissed the Serbian massacres in Kosovo as a 'genocide that never existed'.

Mr Corbyn also backed a motion welcoming England's success in the 1996 European Championships but criticised the 'jingoism and nationalism in the pages of sections of the tabloid press'.

It added it was 'reminiscent of Hitler's use of sport to enhance his evil regime in the 1930s'.

This year Mr Corbyn launched a bid to ban work in temperatures above 30C – or just 27C for physical jobs like on building sites.

The revelations are likely to increase concern among senior members of the Labour party who have warned that Mr Corbyn is unelectable.

The party's growing civil war over Mr Corbyn's surge in support exploded into the open yesterday after Alastair Campbell and Diane Abbott threw insults at each other in a furious online slanging match.

Mr Campbell, Tony Blair's Downing Street spin chief, accused the Labour mayoral candidate of 'talking crap' and accused her of trying to turn the party in a protest movement by backing Mr Corbyn.

It came after Ms Abbott, a prominent supporter of Mr Corbyn's hard-left rhetoric, attacked Mr Campbell over his outspoken plea for Labour activists to vote for 'anyone but Corbyn' to stop the party 'falling off a cliff'.

The war of words came after a shock poll suggested Mr Corbyn had doubled his lead in the Labour leadership race and was on course for a 'knockout victory'.

The YouGov poll of those eligible to vote in the contest gives Mr Corbyn 53 per cent of the first preference votes – enough to win a majority in round one.

Mr Corbyn backed a motion welcoming England's success in the 1996 European Championships but criticised the 'jingoism and nationalism in the pages of sections of the tabloid press'

Mr Corbyn's growing support has sent shock waves through the Labour Party. Former Prime Minister Gordon Brown is understood to be preparing to intervene in a desperate bid to pull the party back from the brink.

Mr Campbell said a victory for the veteran backbench MP would show that Labour had 'given up on being a serious party of government'.

Mr Corbyn has previously attracted criticism for describing the leaders of militant groups Hamas and Hezbollah as his 'friends'.

And he was embroiled in a new controversy earlier this week, as it emerged he had defended controversial Anglican vicar Stephen Sizer, who was disciplined by the church for posting a Facebook link to an article suggesting Israel was responsible for the 9/11 attacks.