Iraqi Prime Minister Ibrahim Jaafari has rejected growing pressure to resign, saying Iraqis must be allowed to choose their leader democratically.
Jaafari will not step aside even though Iraq faces a political vacuum
In an interview with the Guardian newspaper, Mr Jaafari dismissed calls from opponents and some allies to step aside to break a political deadlock.
The Shias' nomination of Mr Jaafari has been a major sticking point in forming a government as he lacks wider support.
He has also been criticised for not doing more to curb sectarian violence.
"There is a decision that was reached by a democratic mechanism and I stand with it," Mr Jaafari told the British newspaper.
"We have to protect democracy in Iraq and it is democracy which should decide who leads Iraq. We have to respect our Iraqi people."
He added: "People will react if they see the rules of democracy being disobeyed. Every politician and every friend of Iraq should not want people to be frustrated.
"Everyone should stick to democratic mechanisms no matter whether they disagree with the person."
Iraq 'in crisis'
Mr Jaafari edged out Iraqi Vice-President Adel Abdul Mahdi - said to be Washington's preferred candidate for the premiership - by one vote in hustings for the leadership contest in February.
Mr Mahdi added his voice to calls for the prime minister to step down on Tuesday - making him the most senior figure in Mr Jaafari's dominant Shia alliance to urge him to withdraw.
His comments came a day after US Secretary of State Condoleezza Rice and British Foreign Secretary Jack Straw ended a visit to Baghdad to press for swifter movement on establishing a government of national unity.
Mr Mahdi told the BBC's HARDtalk TV programme he had urged Mr Jaafari to step down pointing out "that the country is already in crisis and we have to find an end to that".
Mr Jaafari has so far failed to get the approval of minority political groups in parliament in his efforts to form a national unity government, and was also facing rejection within his own United Iraqi Alliance (UIA), Mr Mahdi said.
The BBC's Mike Wooldridge in Baghdad says there are some within the Shia bloc who are concerned that a growing challenge to Mr Jaafari would leave the alliance divided and weak.
Iraq's political parties have been wrangling over forming a new government since December's election.
Kurdish and Sunni Arab parties rejected the ruling Shia-led bloc's nomination of Mr Jaafari as prime minister and have threatened to boycott a government unless he withdraws.
The delay in forming a government is thought to be partly responsible for fuelling the increasing sectarian violence which has struck since February's bombing of a key Shia shrine in Samarra.