With two days until the election and declining support in the polls, Israeli Prime Minister Benjamin Netanyahu on Sunday launched a charm offensive to lure the support of centre-right Kulanu.

With two days until the election and declining support in the polls, Israeli Prime Minister Benjamin Netanyahu on Sunday launched a charm offensive to lure the support of centre-right Kulanu.

As campaigning draws to a close, Netanyahu was to speak at a mass rightwing rally in Tel Aviv with the aim of ramping up waning support for his rightwing Likud.

Ahead of the rally, scheduled to start at 1700 GMT, Netanyahu gave interviews to Israel's two main radio stations in which he said he would be willing to hand the powerful finance portfolio to Kulanu leader Moshe Kahlon.

"I cannot form a government without him. However many seats his party wins, he will get the post of finance minister," Netanyahu told army radio.

A popular former Likud minister, Kahlon -- whose party is forecast to win between eight and 10 seats -- is expected to play the role of kingmaker following Tuesday's vote.

During his tenure as communications minister (2009-2012), Kahlon broke up a years-long monopoly within Israel's mobile phone sector, and his election campaign has focused almost exclusively on economic issues, notably the housing crisis, a key issue for voters.

But Kahlon dismissed the offer as spin, saying Netanyahu had not made good on promises he made in the past.

"Netanyahu already promised me the position of head of the Israel Land Authority and the finance ministry (in the past) and didn't keep his word," he wrote on Facebook, referring to the body which oversees land development.

"It's flattering but it doesn't solve the critical problems facing Israeli society," he said.

With 48 hours left until the election, there was no doubt we would see spin like this," he told public radio.

In a poll published in the top-selling Yediot Aharonot on Friday, the last day on which polls could be legally published before the vote, the centre-left Zionist Union was in the lead taking 26 of the Knesset's 120 seats, followed by 22 for Likud.

Under Israel's complex electoral system, the task of forming a new government does not automatically fall to the party that wins the largest number of votes.

The winner -- and next prime minister -- will be the one who can succeed in cobbling together a coalition commanding a parliamentary majority of at least 61 seats.