STERLING was on the ropes again last night after financial market players reacted to what they saw as a further increase in the chances of Boris Johnson becoming the next Prime Minister.

A poll conducted by Reuters between June 11 and 14 showed the median probability attached to a no-deal Brexit by economists had climbed to 25 per cent, from 15%, amid the ongoing Conservative leadership contest.

A campaign video released earlier this month by former foreign secretary Mr Johnson shows him telling a member of the public: “If I get in we’ll come out, deal or no deal, on October the 31st.”

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The pound sank to its weakest against the US currency since early January, falling as far as $1.2532 last night after the London close close. Much of the fall occurred late yesterday, with sterling having staged a very modest rally earlier to trade around its pre-weekend close of $1.2601.

Chris Beauchamp, chief market analyst at IG, said: “Earlier strength in sterling is slipping away as further leadership polls point towards Boris reaching Number 10 in a short space of time. At this point, it is more a question of whether there will be anyone left to oppose the Blonde Bombshell – [Sunday] night’s debate revealed the weaknesses of the other candidates, especially when compared to Twitter favourite Rory Stewart.

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“Not appearing may prove to be a masterstroke by Boris – allow support to head towards the media darling, while knowing that, in a crunch, the membership itself will plump for the favourite.”

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Sterling hit a five-month low against the euro. The euro was last night trading close to 89.5p.