Leader of the United Kingdom Independence Party (UKIP) Nigel Farage poses during a media launch for an EU referendum poster in London, Britain June 16, 2016. REUTERS/Stefan Wermuth LONDON — Greater control of immigration is more important for Britons than staying in the single market during negotiations for the UK's departure from the European Union, according to a poll on Monday.

Britain has said it will trigger formal negotiations with the EU by the end of March, starting a two-year process to define the future relationship of the UK with its biggest trading partner.

Pollster ORB found that 46 percent of Britons agreed that greater control over immigration was more important than access to free trade, while 39 percent disagreed.

That has flipped since November, when 43 percent disagreed and would prioritise access to free trade, compared to 41 percent who agreed.

"This poll clearly shows that if the country had to choose it would prefer greater control over its borders to access to free trade," said Johnny Heald, managing director of ORB International.

"If we can’t have both, then having greater control over our borders is increasingly the preference."

While Prime Minister Theresa May has been vague on her priorities heading into negotiations, markets have taken fright at hints at a deal which may threaten trade links, often called "hard Brexit".

In an interview with Sky's Sophy Ridge on Sunday, May said she wouldn't be looking to retain "bits" of Britain's EU membership, language that suggested it will be a clean break from 28-nation bloc, not a partial separation. This is because the free movement of EU citizens is one of the EU's 'four freedoms' and cannot be separated from single market membership. This claim caused sterling to slide to a ten-week low.

The poll found that 62 percent of people disapproved of the way the government is handling Brexit negotiations, a level roughly unchanged since November.

The online survey polled 2,075 people, with fieldwork conducted between January 6-8.