Israeli Prime Minister Benjamin Netanyahu has been charged in a series of corruption cases, throwing the country’s paralysed political system into further disarray and threatening the long-time leader’s grip on power.

Capping a three-year investigation, attorney general Avichai Mandelblit charged Mr Netanyahu with fraud, breach of trust and accepting bribes in three different scandals.

It is the first time a sitting Israeli prime minister has been charged with a crime.

According to the indictment, Mr Netanyahu accepted hundreds of thousands of pounds worth of champagne and cigars from billionaire friends, offered to trade favours with a newspaper publisher, and used his influence to help a wealthy telecoms magnate in exchange for favourable coverage on a popular news site.

The indictment does not require Mr Netanyahu to resign but is expected to raise pressure on him to step down.

Benjamin Netanyahu
The decision is likely to have a major impact on Mr Netanyahu’s chances of staying in office (Ronen Zvulun/Pool/AP)

He is due to make a statement later on Thursday, having already called the allegations part of a witch-hunt against him.

Mr Mandelblit said his “heavy-hearted decision” was based solely on professional considerations, and he rejected suggestions the indictment was politically motivated.

He angrily criticised pressure from both Mr Netanyahu’s supporters and foes to sway his decision.

The most serious charges are connected to so-called “Case 4000”, in which Mr Netanyahu is accused of passing regulations that gave his friend, telecoms magnate Shaul Elovitch, benefits worth tens of millions to his company Bezeq.

In return, Bezeq’s news site Walla published favourable articles about the PM and his family.

The indictment also said Mr Netanyahu’s gifts of champagne from billionaires Arnon Milchan and James Packer “turned into a sort of supply line”.

And it accuses Mr Netanyahu of assisting Israeli Mr Milchan, a Hollywood mogul, in extending his US visa.

Two close aides to Mr Netanyahu testified against him in the case.

Israel has recently held two inconclusive elections, with a third likely amid an ongoing political impasse.