More than 30,000 demonstrated in downtown Tel Aviv as thousands more marched in Jerusalem, in the northern city of Haifa and in Nazareth.

Organizers of the protests said that five thousand were marching in Jerusalem towards the home of Prime Minister Benjamin Netanyahu, carrying banners that read "A whole generation wants a future."

Demonstrations over the high cost of living spread in recent weeks throughout Israel, with demonstrators setting up protest camps to demand affordable housing and denounce social inequalities.

On Thursday protesters occupied the roof of the Tel Aviv stock exchange, a day after the powerful Histadrut labour union threw its support behind the demonstrators.

Histadrut said it was issuing Netanyahu with an ultimatum.

"If by Saturday evening, the prime minister has failed to meet with our secretary general Ofer Eini to discuss solutions to lift this social crisis, Histadrut will use all means at our disposal to support the demands of the protesters," a spokeswoman for the union told AFP earlier this week.

AFP