Sterling jumped today after a senior European Union legal adviser said Britain could unilaterally withdraw its Brexit notice.
This eased concern among investors about Britain crashing out of the bloc in March without a deal.
The advice from a European Court of Justice advocate general is non-binding but the prospect of a route out of the Brexit process cheered the market.
The advice came as Prime Minister Theresa May pressed ahead with plans for a parliamentary debate on her divorce deal with the EU.
The pound, which yesterday fell to a one-month low of $1.2697, spiked to a day's high of $1.2840 and traded up 0.7% on the day versus a broadly weaker dollar.
Against the euro it rose 0.2% to a day's high of 88.9 pence.
The growing chance of averting Brexit altogether - potentially via a second referendum - has led some investors to start pricing out the prospect of a damaging "no deal" departure from the EU, analysts said, lifting sterling.
Analysts said that if the European Court decides to support this opinion it will reinforce the hand of those who want the UK parliament to overturn the referendum result and stay in the EU.
That may well be positive for the pound in the short term but could be poisonous for politics in the UK," they added.
May has secured an agreement with EU leaders that will see Britain leave the bloc in March next year with continued close trade ties, but the odds look stacked against her getting it through a deeply divided British parliament.
May's spokesman said today that the British government is not going to revoke its notice to quit the European Union.
Opposition Labour finance spokesman John McDonnell said last week a second Brexit referendum "might be an option we seize upon".
The comments raised expectations the Labour party could back putting Brexit to a second vote though it is unclear what impact such a prospect would have on sterling.
Growing domestic opposition to May's Brexit arrangement has continued to pressure sterling, pulling it down 3% from a November 7 high of $1.3176.
