Turkey's governing party leader Recep Tayyip Erdogan has won a seat in parliament at a by-election, opening the way for him to take over as prime minister.
Erdogan could be Turkey's new prime minister by the end of the week
An aide to Mr Erdogan said in a BBC interview that, as soon as he was sworn in as a parliamentary deputy, current Prime Minister Abdullah Gul would step down and Mr Erdogan could be in the post by Thursday.
It remains unclear if the next few days will also see a new parliamentary vote on the deployment of American troops into northern Iraq from Turkey.
The will of people, who have been kneaded with a fine style befitting our country and a deep prudence filtered through the depths of history, rectified a mistake
Recep Tayyip Erdogan's victory speech
Parliament is expected to vote for a second time on whether to allow the deployment of more than 60,000 US troops on Turkish soil, in preparation for a possible attack on Iraq.
On 1 March, it voted narrowly not to give the necessary authorisation.
The head of the influential Turkish military has said since then that he believes US troops should be deployed.
The economic and political deal negotiated with the US in exchange for troop deployment hangs in the balance.
On Sunday, Mr Erdogan met the US ambassador to Ankara for three and a half hours to discuss the possible deployment of US troops.
Analysts suggest that Mr Erdogan might remove ministers opposed to the deployment.
Mr Erdogan cannot take power before the vote in the south-eastern city of Siirt where the by-election was held is certified on Wednesday.
Following Mr Gul's expected resignation, it will be up to the president to appoint Mr Erdogan as the new prime minister.
This can take up to 45 days according to the Turkish constitution but is expected to happen sooner, Mr Erdogan's aide said.
Mr Erdogan, 49, has been recognised by foreign governments as Turkey's leader since his Justice and Development (AK) Party overwhelmingly won last year's general election.
But until now he was unable to take the post of prime minister as he did not hold a parliamentary seat - having been banned from holding public office due to a 1990 conviction for the incitement of religious hatred.
There were few doubts that Mr Erdogan would win
Parliament last year changed the constitution to allow Mr Erdogan to stand for a parliamentary seat.
"This result is as sweet as a poem," Mr Erdogan said in his victory speech, highlighting the symbolism of his victory, as it was in Siirt that he recited the religious poem that led to his five-year political ban.
He and two other AK Party candidates won some 85% of the vote in the by-election, according to provisional results announced by Siirt Governor Nuri Okutan.
A popular figure in the south-east, Mr Erdogan faced little opposition in a town dogged by unemployment and poverty.