German Chancellor Angela Merkel will this afternoon reject Boris Johnson's request for support in his attempts to remove the Irish backstop from the Brexit deal.

Johnson will visit Berlin in his first overseas visit as prime minister.

He hopes to persuade key EU members including Germany and France to support his efforts to renegotiate the Brexit deal, but both Angela Merkel and French President Emmanuel Macron are likely to rebuff his approach.

"There cannot and will not be new negotiations,' said Florian Hahn, European policy spokesperson for Merkel's party.

The French government reportedly believes a no-deal Brexit is now the most likely outcome, according to an official quoted by Reuters.

German Chancellor Angela Merkel is set to offer a firm rejection of Boris Johnson's latest Brexit demands when he visits Berlin this afternoon, according to her allies.

Johnson will make his first overseas visit as prime minister to the German capital, where Merkel is widely expected to offer a polite but firm rejection to his demand that the EU remove the backstop — a measure designed to avoid the emergence of a hard Irish border — from the withdrawal agreement.

In a four-page letter to EU Council President Donald Tusk published on Monday, Johnson called the Irish backstop measure anti-democratic and "inconsistent with the sovereignty of the UK as a state".

Downing Street hopes that important EU members including Germany and France — where Johnson will travel tomorrow — might ask the EU Commission, which yesterday rejected Johnson's new Brexit demands, to change its position.

Read more: The EU reject Boris Johnson's new Brexit demands before he even sits down with European leaders.

But several senior members of Germany's governing CDU party have already indicated that Merkel does not consider Johnson's latest demands a serious one, and say Germany's position mirrors that of the Commission.

Boris Johnson wants to smash his head through the wall. But the wall is thicker than he thinks

"There cannot and will not be new negotiations. It is completely impossible that the backstop will be removed from the agreement or softened," Florian Hahn, European policy spokesperson for Merkel's party in the Bundestag told the Times.

"Boris Johnson wants to smash his head through the wall. But the wall is thicker than he thinks."

"The letter to the president of the European council is not a serious offer, and Boris Johnson knows it," Norbert Röttgen, an ally of the chancellor, told the Guardian.

"Merkel is politically and emotionally well inclined towards the British, and her willingness to maintain friendly relations between the two countries will be on display on Wednesday," he added.

"But the extent to which the Johnson government is prepared to humiliate itself for a trade deal with the USA has not gone unnoticed in Berlin."

Asked about Johnson's backstop demands, Thomas Matussek, Germany's former ambassador to the UK, told BBC Radio 4: "We cannot throw Ireland under the bus, what message would that send to other members of the EU family if we gave up that sort of loyalty and solidarity?"

He said Britain would be "in for a nasty surprise" if it expected the EU to offer major last-minute concessions.

A French official quoted by Reuters also indicated that Paris now believes that the UK is most likely to leave without a deal in place.

"The scenario that is now becoming the most likely is the no-deal scenario," said an official from President Macron's office who was quoted by Reuters.

'Worrying'

Johnson has repeatedly insisted that as-yet-undefined technological solutions would remove the need for an Irish backstop, despite warnings from officials that such solutions do not yet exist.

In two interviews on Tuesday, Johnson refused to offer any details of what such solutions would look like or what form they might take.

But the Sun reported on Wednesday that Downing Street's latest plan would see the UK ask Ireland to voluntarily diverge from EU rules in order to avoid a hard border.

Read more: Boris Johnson wants Ireland to leave EU trade rules and form a new union with the UK instead after Brexit

Under the plan, the EU would give Ireland "special dispensation" to suspend their trading rules until "alternative arrangements" are established.

Ireland has already moved to reject the plan.

"This is an EU-UK matter, we are the EU, there is no scope for a bilateral agreement," said Senator Neale Richmond, Fine Gael's Brexit spokesperson.

He described the pivot by the UK as "worrying."

Johnson will receive customary military honours outside Merkel's chancellery on Wednesday evening, followed by a meeting in which the pair will discuss Brexit and other European policy issues.

Johnson is due to visit French President Emmanuel Macron in Paris on Thursday for Brexit talks, before heading to the G7 Summit in Biarritz.