BERNE (Reuters) - Switzerland will hold a vote on whether to introduce a basic income for all adults, in a further sign of growing public activism over pay inequality since the financial crisis.

A grassroots committee is calling for all adults in Switzerland to receive an unconditional income of 2,500 Swiss francs (1,741.51 pounds) per month from the state, with the aim of providing a financial safety net for the population.

Organisers submitted more than the 100,000 signatures needed to call a referendum on Friday and tipped a truckload of 8 million five-rappen coins outside the parliament building in Berne, one for each person living in Switzerland.

Under Swiss law, citizens can organise popular initiatives that allow the channelling of public anger into direct political action. The country usually holds several referenda a year.

In March, Swiss voters backed some of the world's strictest controls on executive pay, forcing public companies to give shareholders a binding vote on compensation.

A separate proposal to limit monthly executive pay to no more than what the company's lowest-paid staff earn in a year, the so-called 1:12 initiative, faces a popular vote on November 24.

The initiative's organising committee said the basic income could partly be financed through money from social insurance systems in Switzerland.

The timing of the vote has yet to be announced, pending official guidance from the government. ($1 = 0.9000 Swiss francs)

(Reporting by Denis Balibouse, writing by Alice Baghdjian, editing by Gareth Jones)