Gordon Bajnai said his cabinet would include ministers from all sides
Hungary's former junior coalition partners, the Free Democrats, have finally approved the ruling Socialists' nominee to replace PM Ferenc Gyurcsany.
Economy Minister Gordon Bajnai, a non-aligned technocrat, must now be formally nominated for the post at the Socialists' party conference on Sunday.
The Free Democrats had earlier rejected at least four other Socialist nominees.
Mr Gyurcsany announced this month that he would resign, saying he considered himself a hindrance to further reforms.
He also relinquished the Socialist Party leadership, despite winning overwhelming backing to carry on. A replacement will be elected at the party conference.
A spokesman for Mr Gyurcsany has said he wants to stay in politics, and that "his future role will depend on his Socialist colleagues".
'No time to waste'
The decision of the Free Democrats, whose votes have sustained the minority government since April, to support the Socialists' nomination of Mr Bajnai came after more than a week of political deadlock.
After Mr Gyurcsany announced his intention to resign on 21 March, several other candidates were forced to withdraw or were unable to gain sufficient support.
"The governing council of the Free Democrats will ask the national council to support Gordon Bajnai and his programme so that he can become prime minister," party chairman Gabor Fodor said on Monday.
Mr Gyurcsany will be formally replaced after parliament votes on a so-called constructive no-confidence motion on 14 April.
The procedure allows for a change of prime minister without the need for an early election, which the main opposition conservative Fidesz party wants.
At a news conference, Mr Bajnai said his government would include qualified ministers from both sides of the political spectrum and would be viable only as long as it commanded a clear majority in parliament.
Hungarians have been hurt by debts accumulated in Swiss francs and euros
"Hungary is threatened by the economic crisis. This also means that Hungary has no time to waste," he said.
"Every week wasted... could cost the country hundreds of billions [of forints] and tens of thousands of jobs."
Hungary, whose economy is expected to decline by at least 3.5% this year, needed a $25.1bn (£17.7bn) IMF-led rescue package late last year to avoid collapse. Unemployment has risen to 9.1% in recent months.
Mr Bajnai said quick and credible reforms could restore investor confidence in Hungary and put the country back on track towards joining the euro.
"If we do not act immediately and drastically, then we cannot avert bigger trouble," he added.
"The implementation of the programme will hurt, it will demand sacrifices from many... it will affect every family and every Hungarian but it will have results."