The pound continued its slump against the euro on Monday, following six straight weeks of falls.

It comes as hard-line Brexiter, Boris Johnson, looks increasingly likely to become the UK’s next Prime Minister.

The currency fell 0.4% against the single currency shortly after 5pm UK time to buy €1.118.

Currency traders are mulling over the growing possibility that the UK will leave the EU without a deal on 31 October, which could damage its economy.

With 114, Johnson gained more votes than the next three biggest scores combined, cementing his place as the frontrunner.

“Boris Johnson’s pledge to leave the EU in October — deal or no deal — is a problem,” said Jordan Rochester, a currencies analyst at Nomura to the Financial Times. “Any increase in ‘hard Brexit’ pricing as the October deadline approaches will likely drive sterling lower,” he added.

Yet David Madden, market analyst at CMC Markets, said he thought sterling traders did not think Johnson is intentionally seeking a no-deal exit from the EU, meaning the pound could be lower.

“Even Boris Johnson is saying that he’s looking to ideally to get some kind of deal rather than just plough ahead and hope for a no deal Brexit,” he said.

He said the pound’s poor performance comes as “traders are to an extent looking ahead to Tuesday’s Conservative leadership live debate” on the BBC.

“I think basically there’s going to be little to no interest in sterling until it’s made clear who is going to be the next Prime Minister, and whoever that is, what their position on Brexit is,” he said.

A Bank of America Merrill Lynch survey has found that 62% of fund managers think the chance of the UK crashing out of the EU without a deal is increasing, even though such an outcome lacks support from members of parliament.