Emmanuel Macron warned that the West may have to step in to save Ukraine if Russia makes a breakthrough on the Eastern front, according to reports on Thursday.

The French president produced maps to show opposition leaders, invited to the Elysée Palace, points of potential Russian breakthrough towards Odesa or Kyiv. He told them there should be “no more red lines” on his country’s involvement in the conflict.

“These are maps of the Ukrainian front line freely available anywhere,” the Elysée told The Telegraph.

Speaking after the two-and-a-half-hour meeting, the party chiefs said the talks with Mr Macron left them concerned, with some accusing him of seeking to exploit the conflict for domestic gain ahead of key European elections in June.

The president caused disquiet among many in Europe by refusing to rule out sending Western ground troops to Ukraine, pointing to Russia’s hardening stance. He then urged Ukraine’s allies not to be “cowards” in supporting the country to fight off the Russian invasion.

Some party leaders on Thursday said Mr Macron advocated a “no limits” approach to counter Vladimir Putin, the Russian president, as part of his theory of “strategic ambivalence” – keeping Moscow guessing.

Jordan Bardella, president of the hard-Right National Rally (RN) party, said he had urged Mr Macron “not to go to war with Russia”.

Threatening to send French soldiers “to fight a nuclear power like Russia is irresponsible and extremely dangerous for world peace,” he said.

Fabien Roussel, the Communist Party leader, said that he feared that Mr Macron was “ready to engage in a bellicose escalation which would be very dangerous”.

Marine Tondelier, the leader of the Green Party, recounted Mr Macron saying Putin “obviously has no limits”.

She said it was “extremely worrying” to see the president tell the meeting “we must show we have no limits” too.

‘I left even more worried’

Manuel Bompard, of the hard-Left France Unbowed party, added: “I arrived worried and I left even more worried.”

The Macron camp has made it clear that one aim of meeting the opposition was to “clarify” their position on Ukraine, notably that of the RN, which long admired the Putin administration before the war.

On Wednesday, Prisca Thevenot, a government spokeswoman, said that it was “quite obvious” that the RN was not aligned with Mr Macron’s call to do everything to ensure Russia’s defeat.

Gabriel Attal, the French prime minister, has accused the RN of “supporting Russia more than Ukraine”, even questioning whether “Vladimir Putin’s troops are not already in our country in the guise of Marine Le Pen’s party.

The RN is the largest opposition party in France’s lower house of parliament and leads the Macron alliance by a wide margin in European election polls ahead of the June 9 vote.

Reacting to the reports, Dmitry Peskov, a Kremlin spokesman, said on Thursday that Mr Macron “continues to raise the level of France’s direct involvement” in the Ukraine war.

France’s parliament will have a chance to vote on the country’s Ukraine strategy, including a bilateral security treaty signed with Kyiv last month.

Debates and non-binding votes will take place next Tuesday in the National Assembly lower house and in the Senate upper house on Wednesday.

Later on Thursday, France is set to host a video conference of nearly 30 countries including Ukraine, which will follow up on the initiatives discussed at an international summit hosted by Mr Macron last week.

On Thursday Mr Macron spoke to his predecessors Francois Hollande and Nicolas Sarkozy at the Elysée Palace.

Afterwards, Mr Hollande called for more aid for Ukraine as well as European unity.

“The only possible response is to show that we are with the Ukrainians in total solidarity, that we are giving them all the support they need, without taking part in any combat ourselves,” he said.

Asked about the possibility of sending troops, the Socialist former president said: “My position on military issues is: the less we say, the better.”