Disagreements within Romania's ruling coalition threatened to bring down the government on Wednesday after one of its key figures demanded that Prime Minister Victor Ponta appoint a new deputy.
Coalition members are angry at a delay in appointing Klaus Iohannis, currently mayor of the Transylvanian town of Sibiu, as deputy prime minister.
Senate leader Crin Antonescu, a joint president of the ruling Social Liberal Union (SLU) coalition, threatened to bring down Ponta's government if Iohannis is not appointed by Monday.
If the prime minister fails to do so, "we will immediately demand his resignation," said Antonescu.
Iohannis' nomination was made two weeks ago as part of a reshuffle announced by Antonescu.
But Ponta has failed to confirm the appointments, saying that the post of deputy prime minister does not currently exist.
The quarrel between the two leading members of the coalition comes nine months before a presidential election.
Although Antonescu has already been selected as the sole candidate for the SLU, there is growing pressure within Ponta's Social Democratic Party to nominate its own candidate.
The SLU won Romania's last legislative election with more than 60 percent of the vote.