Erdan and Netanyahu
Erdan and NetanyahuAmit Shavi/Flash 90

A key Likud minister said Thursday that the government is at risk of collapsing if Prime Minister Binyamin Netanyahu's narrow coalition of 61 MKs - the smallest majority possible - is not enlarged soon.

Internal Security Minister Gilad Erdan's comments came amid claims that talks have taken place between Netanyahu and the opposition Zionist Union on joining the coalition. Speculation over such a move began shortly after elections last March, but there have been claims in recent days of fresh negotiations.

"The government will not be able to last much longer," Erdan, a senior Likud member, told Army Radio.

"I hope that Zionist Union or another party will show responsibility and join the government, we don't need to go to elections," he said.

Erdan warned that a unity government was necessary in order to pass the budget and advance the goals of the government.

"If the government is not expanded, it will be very difficult to pass a bi-annual budget and therefore the government will not be able to last much longer. It will be bad for the public."

The minister could not say whether a unity government would be possible, however, given police corruption investigations against Zionist Union chairperson Yitzhak Herzog on suspicions that he breached the funding laws during the 2013 Labor party primaries.

"Unfortunately I don't have any more information about details of the investigation, I won't be able to estimate," said Erdan.

Erdan's comments come a day after Finance Minister Moshe Kahlon (Kulanu) said Wednesday that Herzog "almost" joined the government, but the investigation against him torpedoed the move in late March.

In response to Kahlon's revelation, both Likud and Zionist Union officials dismissed the claims as exaggerated.

Recent polls have shown that the current single-seat majority coalition would not be able to remain in power if elections were held, as the coalition parties all together would not be able to reach a majority.

AFP contributed to this report.