LONDON (Reuters) - Around 200 supporters of leaving the European Union gathered outside the British parliament on Wednesday to demand Prime Minister Theresa May deliver Brexit.

In a June 23 referendum, 51.9 percent, or 17.4 million people, voted to leave the EU while 48.1 percent, or 16.1 million people, voted to stay.

Waving British flags, the protesters chanted "Brexit means Brexit, out, out, out" and "EU no thank you" outside parliament.

"We are here to remind our elected representatives that the country voted to leave. Get on with it," Nigel Birrell, a supporter of Brexit, told Reuters.

May has said she will trigger formal EU divorce talks by the end of March but the Supreme Court is due to consider a government appeal next month over whether parliament must first approve that move.

Another supporter of Brexit, Mo McDonald-Robertson, said outside parliament: "I think they are just putting up lots of obstacles at the moment."

"I just think we need to get out," she told Reuters.

(Reporting by Toby Melville; writing by Guy Faulconbridge; editing by Stephen Addison)