UK government warned parliament cannot vote a third time on same Brexit deal

House of Commons Speaker John Bercow says the motion could not be voted on a third time unless significant changes were made to the agreement

European flags and a British Union flag placed by anti-Brexit remain in the European Union supporters are blown by the wind across the street from the Houses of Parliament. AP

British Prime Minister Theresa May could face an uphill battle to take her Brexit deal back to the House of Commons after Speaker John Bercow signalled he would block a third vote.

Mr Bercow, the arbiter of parliamentary rules, said on Monday that the motion could not be voted on a third time unless significant changes were made to the agreement.

Mrs May said last week that she would put her Brexit deal to a vote again after it was defeated for a second time in parliament.

But in a surprise statement to the Commons, Mr Bercow said: "If the government wishes to bring forward a new proposition that is neither the same, nor substantially the same as that disposed of by the House on March 12, this would be entirely in order."

Solicitor General Robert Buckland hinted the government might try to get around the ruling by dissolving the current parliamentary session and starting again.

Calling the speaker "interventionist", Mr Buckland said there were "ways around this".

Earlier on Monday, a Downing Street spokesman said the government would not commit to another vote on the deal unless it had a chance of success.

Mrs May met her Northern Irish allies, the Democratic Unionist Party, at the weekend to try to secure their backing for the deal.

She seemed to have been supported by the leader of the pro-Brexit European Research Group, Jacob Rees-Mogg, who said that the "bad deal" secured by Mrs May would be preferable to staying in the EU.

But on the same day 23 other Brexiteers from the Conservative Party signed a letter to the Daily Telegraph pledging never to accept the deal, preferring to leave the world's largest trading bloc without an agreement.

Meanwhile, British Trade Minister Liam Fox said on Monday that the UK had agreed to trade agreements with Iceland and Norway in the event of a no-deal Brexit.

The UK wants about 40 EU trade deals before its departure from the bloc, so that current conditions can continue.

In February, it signed similar trade agreements with Liechtenstein and with Switzerland, which is not an EU member but is part of the bloc's single market.

Last week, a majority of parliamentarians voted to reject leaving the EU with no-deal under any circumstances, and to delay the scheduled departure date of March 29.

But any extension of Article 50 must be agreed to by all 27 EU member states.