There are unconfirmed rumors Prime Minister Theresa May will give a speech outside her Downing Street residence on Wednesday evening, the political editor of the Independent newspaper said on Twitter.
Earlier, May asked the EU for a three-month delay to Brexit to buy time to get her twice-rejected divorce deal through parliament, but the request faced immediate resistance from the European Commission.
Britain's parliament will hold an emergency debate on Wednesday on May's decision to request a three-month delay to Brexit, the speaker John Bercow said.
The opposition Labour Party's Brexit spokesman, Keir Starmer, applied for the debate to be held, saying it was vital for parliament to consider the terms of the proposed extension to the Article 50 Brexit negotiation period.
The speaker said the debate would begin shortly and could last up to three hours.