Green Party leader Zack Polanski has released a video of himself urging people to vote for him, speaking in French โ€“ sparking fury about politicians speaking in foreign languages.

It came just hours after the eco-socialist chief made a similar video in Urdu as he hit the campaign trail for the Holborn and St Pancras by-election, where he is standing to replace Sir Keir Starmer as the MP.

Mr Polanski used the social media account of his podcast, Bold Politics, to post the videos, captioning the French intervention with the words “Votez Vert le 8 Octobre”.

But parliamentarians rounded on the display, with Tory MP Alicia Kearns blasting it “preposterous” before cheekily saying: “Sorry, c’est aberrant.”

She added: “Every resident he’s addressing in French and Urdu can hear him in English too. So who exactly is the translation for?”

The top Tory fumed that it was “performative nonsense” as she tore into Mr Polanski online.

Further fury came from Shadow Housing Secretary Katie Lam, who wrote: “When candidates campaign in a foreign language, the vast majority of people can’t understand the promises they make.

“It makes it impossible to hold our would-be representatives to account. We must ban this practice. Politics must be conducted in the language of public life.”

Labour has long held the central London seat in successive elections, but is expected to face a serious threat from the insurgent Greens.

Green Party councillors enjoy successes across the capital in May’s local elections, snapping up seats and even the control of several London authorities.

It has been reported that Labour officials see the by-election as a test of their readiness for an early general election.

Mr Polanski is reportedly hoping to build on the momentum from the May local elections, which saw the party placed second behind Labour in council wards within the constituency.

He is likely to be the most serious electoral threat to Labourโ€™s dominance in the constituency, which the party has held since it was created in 1983.

At the 2024 General Election and recent local elections, Labour voters have moved towards the Greens and independents amid dissatisfaction with the Governmentโ€™s approach to Gaza.

Electors will head to the polls in the constituency on October 8.