Urgently negotiate post-Brexit deal: UK lawmakers to Theresa May

London: Britain must urgently negotiate a post-Brexit transition deal "within a matter of weeks", UK lawmakers said on Thursday.

Obtaining a transition period is an "urgent priority" if the UK is to avoid a no-deal scenario when it exits the European Union in March 2019, according to Parliament's powerful cross-party Treasury Committee.

"Speed is of the essence," Conservative MP and Treasury Committee chair Nicky Morgan said.

But arrangements should be kept "straightforward" to ensure speedy negotiation, as delay caused by "arguments over arcane points of principle" would damage the economy, she added.

The government should be prepared to accept the transition terms offered by the remaining 27 EU members, even if this means retaining the jurisdiction of the European Court of Justice and the supremacy of EU law, the committee said.

"That is a price worth paying for stability and certainty after 30 March 2019," Morgan added.

Although the report calls for a "standstill" deal to incorporate existing EU treaties into the withdrawal agreement, it also says that the UK should be able to start establishing "independent trade relationships" during the transition.

Certain sectors including financial services, particularly exposed to trade with the EU, may need an "adaptation period" to be added on to the time-limited transition period.

Prime Minister Theresa May has committed to seeking a two-year transition for the UK to give businesses time to adapt.

A no-deal scenario would mean Britain and the EU would fall back to World Trade Organisation rules to trade with each other, creating a series of trade barriers such as a 10 percent tariff on imports and exports of cars.

Some 130,000 UK firms which currently trade only with the EU would be dealing with customs procedures for the first time if there is a no-deal scenario in March 2019, according to the Treasury Committee report.

A new round of negotiations covering Britain's future trading relationship with the remaining 27 members of the bloc will open on Friday at a summit in Brussels, but EU negotiating guidelines have been revised to say talks on trade will not start until March.