Labour leadership candidate plans to block talks if no second vote

A leadership candidate for Britain's opposition Labour party, Owen Smith, said on Wednesday he would try to get parliament to block talks on leaving the European Union unless the government promises a second referendum or election.

On June 23, 52 percent of Britons voted to leave the EU, but Smith has said some electors were duped into backing the Brexit campaign and may think twice due to signs that Britain's economy could slow since the vote.

Prime Minister Theresa May will wait until next year to trigger Article 50, the formal clause by which a country leaves the European Union, but it is unclear if the process can be started without a parliamentary vote.

"We will vote in Parliament to block any attempt to invoke Article 50 until Theresa May commits to a second referendum or a general election on whatever EU exit deal emerges at the end of the process," Smith said in a statement.

He said there was too much uncertainty over what Brexit will involve.

"Nobody knows what Brexit looks like. It could involve trashing workers' rights and environmental protections, opening our NHS (health service) up to foreign competition, making it harder for us to trade with our neighbours and damaging our economy."

May's Conservative government has a slender working majority of 17 in the 650-seat chamber but the majority of British lawmakers supported remaining in the EU.

Labour was thrust into one of the biggest crises in its 116-year history after the referendum, when most of the party's lawmakers responded by voting to withdraw support for incumbent left-wing leader Jeremy Corbyn, prompting the second leadership contest in a year. Smith is his only challenger.