Labour will introduce new bank holidays to mark the patron saints of England, Wales, Scotland and Ireland if it wins the next general election, Jeremy Corbyn is to announce.

The party leader will tell a union conference on Monday, which is St George’s Day, that Britain’s workers deserve a day off after eight years of “damaging Tory austerity”.

Labour will ask for the support of the devolved governments so that the same four holidays can be enjoyed across the United Kingdom.

Under Labour’s proposals, UK-wide public holidays would be held on St David’s Day (1 March), St Patrick’s Day (17 March), St George’s Day (23 April) and St Andrew’s Day (30 November).

With eight public holidays, the UK has the fewest of any G20 or EU country, Corbyn will tell the annual conference of the Communication Workers Union in Bournemouth.

He will say: “If we win the next election, St George’s Day will become a national holiday for Britain’s workers. It will be a day where we can all show our pride and celebrate our country’s tradition of fairness, inclusivity and social justice.

“Eight years of Tory austerity, which Labour will bring to an end, have had a disastrous effect on our vital public services and workers have paid a heavy price in the cost of living and their working lives. We will give our workers four extra days’ paid holiday.”

Corbyn said the Windrush scandal and the “sickening ‘go home vans” showed that the government’s “patriotic posturing” was a sham.

He will add: “We need to end the Conservatives’ constant pandering to a rich elite at the top and their attempts to divide the rest of us, creating a ‘hostile environment’ for people who come to contribute to our country.

“So let me say to the Windrush generation and to everyone who has come to this country to make a contribution: you are welcome. You have equal rights and under Labour you will never be treated like second-class citizens. We will never allow people to be divided on the basis of race or religion.”

Corbyn will also recommit Labour to bring Royal Mail into public ownership.