John McDonnell, Shadow Chancellor of the Exchequer, appears on BBC TV's The Andrew Marr Show in London, Britain February 17, 2019. Jeff Overs/BBC/Handout via REUTERS.

LONDON (Reuters) - Britain’s opposition Labour Party does not want a second Brexit referendum but has been forced into supporting one by Prime Minister Theresa May running down the clock on negotiations, Labour’s finance spokesman John McDonnell said on Sunday.

This week Labour said it would back a second referendum in order to try to prevent either a ‘no deal’ or May’s deal. With less than a month until Britain is due to leave on March 29, May is yet to win parliament’s approval for her deal.

“We have been forced into this by Theresa May delaying, running down the clock,” McDonnell told Sky News, saying Labour is still pushing to get its alternative Brexit plan adopted.

“If we can’t get that we will have to break the log jam by going back to the people. It is not what we want but it is what we have been forced into.”