LONDON, Jan. 8 (Xinhua) -- Influential business body London First on Tuesday called for a second referendum in the event the Brexit deal is voted down in the UK parliament later this month and no workable alternative plan is found.

British Prime Minister Theresa May has said that a vote on her Brexit deal would go ahead in the House of Commons as planned next week, warning that her country would be in "uncharted" territory if MPs reject it.

Opposition MPs and politicians from her own Conservative Party have threatened to oppose her Brexit deal. If that happens, it will make the prospect of a no-deal Brexit more likely than ever.

London First, a business campaign group representing over 200 of the capital's leading employers, called on the government to "stop the clock" on the UK's withdrawal from the EU to avoid the economic damage that would be caused as a result of leaving without a deal.

The campaign group had supported the EU Withdrawal Agreement last year, though stressing that the deal was far from perfect. The government postponed a parliament vote in December amid fears it could suffer a crushing defeat, and the prospect of approval at next week's vote looks increasingly uncertain.

Jasmine Whitbread, chief executive of London First, said: "The political reality is that the agreement now looks unable to secure parliamentary support and the country is left teetering on a cliff edge.

"If we don't have a deal next week, it's time to stop the clock and revoke Article 50, so the government can stop spending billions on last-ditch efforts to manage a no deal and instead come up with a plan that works," Whitbread said.

"If such a plan cannot be found, the decision must go back to the people. Continued uncertainty is never welcome, but it will be vastly less damaging than crashing out of the EU," Whitbread said.

London First has been calling for a Brexit deal which retains the benefits of the customs union, safeguards the service sector and keeps the UK open to the talent and skills the UK economy needs. It believes that trading on World Trade Organization (WTO) terms would mean huge practical and logistical problems for UK companies.

British Secretary of State for International Trade Liam Fox told the Sunday Times in late December that there is a 50-50 chance the UK will not leave the EU on March 29 if MPs reject Theresa May's Brexit deal in January.