LONDON, Sept 24 (Reuters) - The leader of Britain's opposition Labour Party, Jeremy Corbyn, said on Sunday a transitional period designed to smooth the country's exit from the European Union should last as long as necessary.

"You have to stay in a transitional period as long as necessary ... I think it's impossible for anyone to put an actual figure on that," Corbyn told the BBC. He said he did not envisage a period lasting as long as 10 years.

Last week Prime Minister Theresa May set out plans for a roughly two-year transition period. (Reporting by William James, editing by Elizabeth Piper)