Senior Labour figures have warned that leaving the European Union would lead to further cuts in public spending, an emergency budget and higher taxes.

At a press conference on Friday (10 June), party deputy leader Tom Watson and shadow cabinet colleagues presented figures from the Institute for Fiscal Studies (IFS), which set out the implication an emergency Brexit budget would have on the UK economy.

According to the IFS, should Britain vote to leave the EU on 23 June, an estimated £18bn (€23bn, $26bn) of spending cuts and tax rises could be implemented and working people would be among the worst affected by deeper cuts to public services, tax rises and social security cuts.

Departmental resource budgets would fall by 2.8% in 2019-20 on top of existing plans. The Department of Health and the Department for Education would be cut by £3.5bn and by £1.6bn respectively, while the Home Office and the Ministry of Defence will see their budgets slashed by £300m and £800m.

"Austerity is a political choice, not an economic necessity," Watson said.

"If the UK was to vote to leave the European Union we know the Tories would choose more austerity to deal with the economic fall-out and meet their discredited fiscal promises.

"Leave campaigners like Boris Johnson and Michael Gove need to tell the British public what a Tory Brexit would mean in terms of the public finances and further austerity."

Watson added a Brexit would have serious financial consequences on working-class families, claiming high-profile members of the 'Leave' campaign were happy for others to pay.

"This is the price of Tory Brexit. It is a price that Boris Johnson, Michael Gove and the like are happy for other people to pay," he said.

"Britain is faced with a fundamental choice: whether to choose jobs and growth by voting to remain, or to choose exit and the Tory cuts and tax rises that would bring. Working people would be hurt by a vote to leave. Labour won't stand by while that happens so we're redoubling our efforts and saying loud and clear: we're in for Britain."

The warning from the Labour hierarchy comes just a day after he National Institute of Economic and Social Research (NIESR) said low-income families could see their benefits slashed by hundreds of pounds should Britain vote to leave the 28-country bloc.

According to the economic think tank, some households could lose up to £2,771 a year, as a decline in national income could see the government implement drastic cuts to the welfare budget over the next three and a half years.

Meanwhile, in a separate event, former Labour leader Ed Milliband also warned a Brexit would see the Conservative party move further to the right and reduce workers' rights.

"Let's be clear what the Leave agenda would mean for working people," Milliband said in a speech in London.

"They want out of Europe so we can be out of the social chapter, as Boris Johnson said [...] in 2012. Their competitiveness strategy for Britain is deregulation and the erosion of rights of working people."

However, Labour MP John Mann has declared his support for the Brexit campaign, claiming a "revolution" was underway.

"It shouldn't come as a shock how many Labour voters will vote," he said. "Because a people's revolution is under way. This is about returning power to the people."