Voters go to the polls again in 39 constituencies around Iran on Friday, in a run-off to decide seats where none of the candidates won the necessary 25 per cent of the votes in the February general election.
By Jim Muir
BBC correspondent in Tehran
The second round of voting will not change the overall outcome of the election, which saw conservatives regain control of the Majlis, or parliament.
Reformist candidates were disqualified during the campaign
Some 2,300 would-be candidates - almost all reformists - were disqualified in advance by a right-wing vetting body.
The reformists are expected to do equally badly in the run-off, winning fewer than 20 of the 60 or so seats being contested (some of the constituencies return several members to the Majlis).
One of the 30 seats in the Greater Tehran constituency remained undecided after the February poll.
The outgoing Majlis voted last month not to fill that vacancy in Friday's second round of voting, because of the expense and effort involved in holding a ballot in such a large constituency.
Instead, the seat will be contested simultaneously with the next presidential election in May or June of next year.
The Interior Ministry said it expected the run-off polling to go smoothly on Friday because all the procedural disputes had already been exhausted in the first round.
The ministry is reformist-dominated and was involved in fierce arguments with the right-wing Council of Guardians over the February election and acrimonious recriminations from the February vote have continued.
The Interior Minister, Abdol Vahed Musavi-Lari, said this week that his Ministry had not been able to defend the citizens' rights and apply the law in the face of the mass disqualifications ordered by the Council of Guardians.
Abdol Musavi-Lari complained about lack of citizens rights
The Council plays a supervisory role in elections which are administered by the Interior Ministry.
The head of the Council of Guardians, Ayatollah Ahmad Jannati, meanwhile urged the Judiciary (another right-wing stronghold) to arrest people who he said had been guilty of pressuring voters with inducements and threats in the first round of the election.
He was believed to be referring to some of the 40-odd seats where reformists won.
Despite the huge number of disputed, one-sided disqualifications in the first round, the Iranian public remained largely unmoved.
Reformist members of the outgoing Majlis, around 80 of whom were among those disqualified, staged a sit-in at parliament and resigned.
But there was no popular demonstration of support.
Because they had been unable to deliver on the hopes they had raised, the reformists had largely lost the backing of a public which gave them an overwhelming election victory in 2000.
The inauguration of the new, conservative-dominated Majlis later this month will leave Mohammad Khatami, the reformist symbol, cast in the role of lame-duck president until he is obliged to stand down next year.
But some Iranian analysts do not believe the reformists are completely finished.
They expect a coalescence of the political centre, linking moderate reformists with pragmatic conservatives who recognise the need for changes to meet the public mood and expectations.
Since the February elections, right-wing bodies have made a number of moves long urged by the reformists.
Some well-known political prisoners have been allowed out on furlough, and the Judiciary and the Council of Guardians have taken steps to ban the use of torture on detainees and suspects.