Priti Patel (2nd left) with other leading Brexit campaigners WPA Pool / Getty MANCHESTER — Theresa May should make big cuts to public spending and give a "dose of free market economics" to public services after Brexit, one of her Cabinet members has urged.

International Development Secretary Priti Patel told a fringe event at Conservative conference that current levels of public spending were "not sustainable" and the government should be honest with the public that they would be slashed.

Patel, who was a leading Brexit campaigner, said the "never-ending cash cow of public spending" must end, adding that "the expectations with the British electorate we should be pretty clear [that] we are promising a whole range of things to the electorate which today won't be sustainable in 10, 20 years time."

Asked if the Conservatives would promise dramatic cuts to public spending at the next election, Patel replied that "anything is possible."

The government has promised to adopt all EU laws and regulations as part of the Great Repeal Bill. However, Patel suggested the government should be proactive about stripping them back.

Speaking to IEA director Mark Littlewood, Patel also agreed that Brexit was an opportunity for widespread "deregulation."

"That's absolutely right and that's the case I made when I campaigned to leave the European Union," she said.

She added: "It would be terrible to leave it to Sir Humphrey and officials. That is not the right approach."

She said MPs should "challenge a lot of these regulations. They are out of date and we don't need them."

Patel said the party needed to push the market into all areas of the public sector.

"We need to apply new thinking and new ideas to renew our party across areas of policy, whether it's housing, health, social care, housing, transport..." she said.

"These outcomes need a dose of free-market economics ... to provide answers to the challenges we face."

Labour said Patel's comments revealed the party's "true agenda" for Brexit.

"Priti Patel's comments have exposed their true agenda: even more cuts for the many, tax giveaways for the few, and a bonfire of rights and protections for workers and consumers," Labour’s National Campaign Co-Coordinator, Jon Trickett, said.

"By asking those with the broadest shoulders to pay a little more, Labour will invest in our public services, which have been cut to the bone by seven years of Tory rule."