The opposition's plan is to force Prime Minister Johnson by a vote in the afternoon to ask the EU for extended negotiation time until the end of January 2020. Something the newly-appointed head of government says bluntly refuses. Should he lose the vote, the election is likely to wait.

The Labor-led opposition hopes to reach a majority with the help of a number of Conservative Tory members who are also against a contractless Brexit, including former Finance Minister Philip Hammond.

To force rebel party mates to line up, Boris Johnson has said whoever refuses to support the party line will not be allowed to run for Tories in the next election.

Continued fall for the pound

The high level of nervousness is not least apparent from the fact that the British pound on Tuesday fell to the lowest level in two years against the US dollar.

- Everyone sells the pound as we have been forced to realize that, without the political risk picture, Brexit without a deal is possible, says currency strategist Junichi Ishikawa at the investment bank IG Securities in Tokyo to Reuters.