An anti-Brexit demonstrator waves flags outside the Houses of Parliament, in London, Britain, September 10, 2018. REUTERS/Hannah McKay

LONDON (Reuters) - British Prime Minister Theresa May urgently needs to develop an alternative approach to leaving the European Union in case her current negotiating strategy fails, the chairman of parliament’s Brexit committee said on Tuesday.

May is under pressure from both eurosceptics and pro-Europeans in her party and the European Commission to deviate from her negotiating stance - known as the Chequers plan - as she tries to secure an agreement on how to separate from the EU.

The government is pursuing a strategy that would sign British businesses up to a common rule book, to keep trade flowing across borders. The alternative, May has said, is that Britain will leave without a deal on March 29 next year.

Many, including the International Monetary Fund, have argued that such a ‘no-deal’ outcome would badly damage the world’s fifth largest economy.

On Tuesday, the Brexit committee published a report highlighting that time was running out to secure a deal before an October/November deadline and that significant obstacles needed to be overcome to reach a deal.

“If the Chequers plan is not acceptable as a basis for that, then the Government will need to find a different approach urgently,” committee chairman Hilary Benn said.

Benn said two alternatives to the current strategy were a customs union and alignment on relevant EU rules, or membership of the European Economic Area coupled with a customs union. Neither approach is consistent with current government policy.

The committee, which scrutinises and advises on policy but has no legislative power, was split over the impact that a no-deal Brexit would have, but agreed by a narrow majority that it would be “chaotic and damaging”.