A pariah to Britain's mainstream politicians, a maverick with a silver tongue and a stranger to self-doubt, "Gorgeous George" Galloway is back at Westminster, relishing a remarkable electoral comeback and, as ever, waging war on war.

Last month, he stunned the Labour Party that expelled him for opposing its Iraq war with an election victory in one of its inner-city strongholds. Now, after two years out of parliament, when it seemed he might best be remembered for an embarrassing moment in a catsuit on reality TV, he is back in the House of Commons demanding another prime minister end another conflict.

"This bloody morgue of Afghanistan!" the veteran left-winger thundered on Wednesday in his rolling Scots brogue at David Cameron.

The premier's respectful nod in return to the oratory of the new member for Bradford West spoke of an awareness of Galloway's knack for voicing popular sentiment, notably among Muslim voters. And he can afford to welcome Galloway's return, knowing the lone MP for the fringe-left Respect Party poses a greater threat to Labour leader Ed Miliband than to his Conservatives.

Many had assumed British politics no longer held a berth for the 57-year-old Galloway, who previously sat in parliament for 23 controversy-filled years and who made a particular name for savaging George W Bush and Tony Blair. He called them "wolves" for attacking Iraq, only to later apologise — to wolves.

The four-times married Galloway, a sharp dresser whose appeal to women earned him the nickname "Gorgeous George" when he was a young and pushy charity organiser in the 1980s, was thrown out of Blair's Labour Party in 2003 for opposing the Iraq war. After taking a London seat for Respect in 2005, he failed to get back into parliament in the 2010 general election.

Few saw a way back for man who was cleared of accusations of impropriety over his fund-raising, notably a charge of taking money diverted by Saddam Hussein from Iraq's UN Oil-for-Food Programme — he sued for libel and won — but was suspended by parliament briefly in 2007 for other infringements of its rules.

Yet little has been predictable about Galloway's career: one year he was laying into US senators who questioned him about his meetings with Saddam Hussein — unlike US official Donald Rumsfeld, he hadn't met the dictator "to sell him guns" — and the next he was prancing in a leotard on a celebrity television show, lapping milk from an actress's hand and pretending to be a cat.

Now Galloway is back. He has a makeshift office in the Westminster legislature's busiest canteen and prowls the halls of the mother of all parliaments after a landslide by-election victory that saw him seize control of one of Labour's safest seats — a victory all the sweeter for him as pollsters failed to predict it until the moment his 56-per cent result was announced.

His re-emergence, winning twice as many votes as the Muslim Labour candidate whom the Scottish teetotaler derided as "never out of the pub," sent shivers through Labour. Many feared that defeat in working class Bradford was the clearest sign yet that new leader Miliband cannot return his party to power in 2015.

It also underlined the anger of British Muslims against an interventionist foreign policy under both Labour and now Cameron's Conservatives, and a growing desire among all Britons for an end to their army's stuttering Afghan venture.

"As I was saying, Mr Speaker," Galloway bellowed from the backbenches, his voice booming across the wood-panelled walls of the lower house in the most popular weekly set-piece debate in British politics — Prime Minister's Questions.

"Will the prime minister reconsider his current planning of our withdrawal from this morgue, this bloody morgue of Afghanistan?"

He accused the mainstream parties, including Cameron's Liberal Democrat coalition partners, of deliberately misleading the public over the progress made in a decade in Afghanistan: "There is an iron-clad consensus across the three front benches about what they now call a 'mission' but, given the amount of blood on the ground and the rapidly deteriorating military situation, most of us call a war in Afghanistan."

Cameron's cautious, straight response (he often enjoys lampooning other loose cannons, including on his own benches) was a tribute to how seriously Galloway, with what commentators have called his "gift of the Glasgow gab," is taken.

"Let me congratulate the honourable gentleman on his stunning by-election victory and his return to this House of Commons and I know he always speaks with great power and great force," the prime minister said. "But on this issue, I have to say, I profoundly disagree with him.

"I would urge him not to play to the gallery on this issue, but to speak for the work our forces are doing to make Afghanistan a safer country."

Born in what he called a "slum" in the port city of Dundee, Galloway joined Labour at just 13 and quickly sped up the ranks of a long-serving "awkward squad" of hardline socialists disgusted with the party's liberal modernisers — a prefigurement of his terminal falling out with "Tony Blair's lie machine."

He courted controversy with outspoken criticism of Israel, defending the Palestinian cause and Iran, for whose Press TV he now presents "The Real Deal" — "Shooting from the lip ... News and views that you can not find in the corporate media."

As Saddam Hussein battled international sanctions, he found an ally in Galloway, who met him in Iraq in 1994 and declared: "Sir, I salute your courage, your strength, your indefatigability." That earned him the ironic soubriquet "the member for Baghdad North."

After Saddam's fall, Galloway insisted he had had no doubt the man was a "bestial dictator," but that sanctions and war had not been the way to remove him.

A televised bravura performance in 2005 in front of a US Senate committee investigating abuses of the Oil-for-Food Programme won him the admiration of many British Muslims disenchanted with the West's "war on terror."

Having called the committee chairman a "lickspittle of George W Bush," Galloway eschewed the deference to which US senators are normally accustomed and lambasted the "pack of lies" on which, he said, the United States had based its war in Iraq.

Twice married to Arab women, the Roman Catholic-born Galloway has become a champion of the interests of Britain's fast-growing Muslim population — currently estimated at around four per cent — and used that to devastating effect in Bradford.

Never one to underestimate himself, he compared his victory on 29 March to the Arab uprisings of the past year: "This, the most sensational result in British by-election history, bar none, represents the Bradford Spring," he said.

"This is an uprising amongst thousands of people ... who have demonstrated in this mammoth majority, this mammoth vote, a total rejection of the major parties on the British political scene."