Sadiq Khan has been an MP for less than three years, but has quickly established himself as a rising star in the Labour Party.
Mr Khan was a prominent human rights lawyer
He made his name as a human rights lawyer before becoming one of the first Muslim ministers - and has dedicated much time to improving relations between the police and Muslim communities across the country.
The 37-year-old was voted "newcomer of the year" in the 2005 Spectator magazine awards, within months of being elected to the south London seat of Tooting.
He might be a government whip now, in charge of making sure Labour MPs vote in line with the government, but he has not been afraid of ruffling a few feathers, particularly on issues concerning community cohesion.
In the weeks that followed the 2005 bomb attacks on London's underground network, Mr Khan was warning of widespread concern about some of the anti-terrorism measures planned by ministers.
He also raised concerns about Britain's policy towards the Middle East, during air attacks by Israel against Lebanon's militant Hezbollah group.
And he was one of three Muslim MPs to sign an open letter to then prime minister Tony Blair in August 2006 suggesting British foreign policy was putting civilian lives at risk in the UK and abroad - a move that was criticised by the then home secretary as "misjudged".
Born in Tooting in 1970, Mr Khan grew up on Earlsfield's Henry Prince Estate and went to local primary schools and comprehensive before going on to study law and trained as a human rights solicitor.
Mr Khan was among Muslim MPs who raised concerns with Tony Blair
He co-founded his firm Christian Khan with fellow human rights lawyer Louise Christian, was chairman of Liberty, the civil liberties group, for three years, as well as being a chairman of the Muslim Council of Britain's legal affairs committee.
Now a government whip, he has voted to support the government on controversial issues such as the introduction of identity cards and in favour of its anti-terrorism laws in Parliament.
Mr Khan has been campaigning against the laws under which the US wants to extradite his constituent Babar Ahmad. Mr Ahmad is accused of running websites raising money for the Taleban but faces no charges in the UK.
UK laws introduced in 2003, the year Mr Ahmad was arrested, allow US prosecutors to request extradition without having to prove in UK courts there is a case to answer.
Critics say it makes it far easier for the US to extradite a suspect from Britain than the other way around - the same laws were used to extradite the NatWest Three following the collapse of Enron.
It is reported that Scotland Yard's anti-terrorist branch bugged conversations between Mr Khan and computer expert Mr Ahmad during visits to Woodhill Prison in Milton Keynes in 2005 and 2006.
Mr Khan told the BBC he didn't know anything about it until his wife Saadiya saw the story on the news and said it was important to await the outcome of an inquiry into the claims.
But he said, if it was true, it could have serious implications for the relationship between MPs and their constituents - some of whom may be suffering domestic violence, serious neighbourhood disputes or disputes with the police.
"Constituents should feel comfortable about their ability to go and see their member of Parliament and speak with honesty and candour about their issues," he said.
"If it was the case...that constituents were having their conversations with members of Parliament bugged, then it clearly means the whole relationship and the basis on which that relationship has been based for decades and, dare I say centuries, is undermined."
Mr Khan, who was a Tooting councillor before becoming an MP, has been married since 1994 and has two daughters.
He was parliamentary private secretary to then Commons leader Jack Straw, before taking up a ministerial role in the government whip's office, with responsibilities for managing Ministry of Justice legislation.
He plays for the UK Parliament Football Club as well as the Lords and Commons cricket clubs and has links with the Labour-affiliated Fabian Society, Progress, as well as being a member of the GMB and Unison trade unions.