The Labour Party has apologised to the people of Blaenau Gwent for imposing an all-woman shortlist on the constituency in the 2005 general election.
Peter Law defeated Labour's Maggie Jones in Blaenau Gwent
Welsh Secretary Peter Hain said that while he thought having an all-woman shortlist was an honourable objective, Labour "got it wrong".
Mr Hain told BBC Wales' Politics Show he was issuing the apology on behalf of Labour at the highest levels.
Independent Peter Law defeated Labour's Maggie Jones at the election.
Blaenau Gwent was Labour's parliamentary seat in Wales, but Mr Law overturned a 19,000 majority in defeating Ms Jones.
'Listen to people'
Mr Hain said on Sunday: "I'm saying sorry to them (people in Blaenau Gwent). We got it wrong last time.
"We sought to present a choice of women only and we over-rode local party wishes and the wishes of the people of Blaenau Gwent.
"The first law of politics is you listen to the people.
Mr Hain issued the apology on behalf of Labour
"The voters are in charge and that is why the selection of our candidate tomorrow night will be entirely by the party in Blaenau Gwent reflecting the wishes of the people in Blaenau Gwent which didn't happen last time."
Mr Hain said the apology was coming from him "as secretary of state for Wales, speaking for Welsh Labour and on behalf of the national executive, the party leadership and the government".
In the interview, Mr Hain also offered an olive branch to those expelled in 2005 for supporting Mr Law when he left Labour over the issue of all-woman shortlists to contest the Blaenau Gwent seat.
While stopping short of declaring an amnesty, the Welsh secretary said there was no reason why those who had been expelled could not come back to Labour.
BBC Wales understands that further steps will be taken in the coming days to bring supporters of Mr Law back into the fold.
Reacting to the interview, Dai Davies, spokesman for Blaenau Gwent's People's Voice Group which supported Mr Law, said that the apology was "hypocritical" and reflected Labour's desire for self-preservation.
Mr Davies, Mr Law's former parliamentary agent and likely by-election candidate, added that the Labour Party could have done this "five, six, 10 months ago".
He added that the apology reflected the party's "desperation" to win the upcoming double by-election in the seat caused by Mr Law's death last month.
Parties contesting the parliamentary and Welsh assembly seats in Blaenau Gwent have begun the process of selecting their candidates.
John Hopkins will be the Labour candidate for the seat in the assembly by-election while the party is due to choose its parliamentary candidate on Monday.
The Liberal Democrats have chosen Amy Kitcher to fight the parliamentary seat with Abertillery councillor Steve Bard contesting the assembly seat.
The Conservatives and Plaid Cymru are expected to confirm their candidates by the end of the week.
The Blaenau Gwent People's Voice group has also said it will put candidates forward.