British voters do not regret backing Brexit and do not want a second referendum on EU membership, a leading polls expert said Wednesday as he presented the results of a new study.

Professor John Curtice of Glasgow's Strathclyde University analysed a series of polls since the June 23 referendum when 52 percent voted to leave the European Union.

"We remain divided three months on -- very few minds have been changed," he told a briefing in London.

He also revealed that people were now adjusting their expectations over pledges during the campaign to cut immigration and reallocate funds to the National Health Service which currently go to the EU.

"Before the referendum, over half the public expected the level of immigration to fall as a consequence of Brexit," Curtice said. "Now, that number has fallen to around 45 percent."

Asked what they expected of Brexit, most Britons mentioned the end of freedom of movement but also continued access to the single market.

"There is quite an appetite for some kind of compromise (with access to the single market) and some control over immigration," he said.

European leaders including European Commission chief Jean-Claude Juncker insist they will not accept limits on the free movement of people, a core EU principle, in any deal that allows Britain access to the single market.

Prime Minister Theresa May's government contains both supporters of a "hard" Brexit which would involve severing ties with EU institutions and those who would prefer a "soft" departure that could involve continued access to the single market.

May says she will not trigger the formal process for leaving the EU before the end of this year.

Triggering Article 50 of the EU's Lisbon Treaty would begin a two-year countdown to actual Brexit.