EDINBURGH (Reuters) - British pessimism on the economic consequences of leaving the European Union is growing, but Britons have not broadly changed their minds about how they voted, Britain’s leading pollster John Curtice said on Tuesday.

Protesters wave the EU and Union flags outside the Palace of Westminster, London, Britain, December 20, 2017. REUTERS/Peter Nicholls

British Prime Minister Theresa May is trying to deliver a new trading relationship with the EU with her authority diminished by party infighting, the resignation of key allies, a fractious parliament, a divided electorate and a tight timetable before the March 2019 Brexit deadline.

Research carried out in October by the National Centre for Social Research (NatCen), where Curtice is senior research fellow, found Britons increasingly critical of the UK government’s handling of Brexit.

“Although voters ... blame the government, blame the EU, ‘Leave’ voters for the most part have not changed their minds about their decision,” Curtice, who is also a professor of politics at Strathclyde University, told a presentation in the Scottish capital. “‘Leave’ voters are saying the government is mucking up, not that the decision we made (to leave the EU) was wrong.”

The NatCen poll found 52 percent of Britons thought the economy would be worse off after Brexit, versus 46 percent in a similar poll last February. That compared with 58 percent of Scots, polled separately, unchanged from February.

As for Scotland, which voted to stay in the EU, Brexit is not a catalyst for Scottish independence from the UK but it has not dampened separatist fervor either, the poll found. Support for secession is at about 44 percent versus 45 percent in a 2014 independence referendum.

The poll also showed 52 percent of Britons now expect a “bad deal” versus 55 percent of Scots. That compares with 37 percent of Britons last February.

NatCen also found that support for a different Scottish immigration policy from the rest of the UK after Brexit, as favored by the Scottish government, does not have majority support either and most Scots want the same immigration policy nationwide.

In Britain as a whole, 61 percent of those polled thought Brexit had been badly handled by the UK government, up from 41 percent in February and versus 69 percent in Scotland.

ScotCen polled 859 people, all of whom had been interviewed as part of the 2015 or 2016 Scottish Social Attitudes survey, which is carried out face to face.