Green councillors could torpedo Labour plans to build a “new town” in north London as the party prepares to team up with the Conservatives to vote them down.
Enfield was one of seven councils in the capital to fall to no overall political control at the local elections last week as Labour's vote share in the city collapsed.
Negotiations over who will lead the boroughs that failed to elect a party with an outright majority are ongoing and unusual cross-party alliances being formed.
The Labour government has plans to build up to 21,000 homes on Greenbelt land in Crews Hill, Enfield.
The scheme was unveiled in March as ministers faced criticism for lagging behind in its promise to build 1.5 million new homes by the end this parliament.
Conservative councillors, who now form the largest group in the town hall with 31 seats but no overall majority, have opposed the proposals along with the Greens.
Labour won 27 seats on the local authority, meaning the five Green councillors will cast deciding votes on policies.
Tories and Greens are against the plans to build on the Enfield Greenbelt and have indicated they will team up to vote developments down.
As a large housing scheme, the Crews Hill development would be sent to Sir Sadiq Khan for final approval but the Mayor has also previously spoken out against building on the Greenbelt.
Both the Greens and Tories are also aligned in opposing Tottenham Hotspur’s plans to build a training centre for its women’s team near a former golf course in the Whitewebb’s Park area.
It was approved in February last year but a judicial review brought by campaigners challenging the development is due to be heard at the High Court in June.
Sarah Jons, who has been selected the leader of the Enfield Greens, said: “There are several possible ways a council under no overall control can operate in practice.
“It is a complex situation, and discussions are at an early stage. We are approaching those discussions carefully and constructively, with our focus on what is best for Enfield residents.”
Sir Keir Starmer's party failed to retain control of half of the 21 London local authorities it won in 2022 in a bruising round of results.
Overall Labour lost 1,498 council seats across England, putting the Prime Minister’s leadership in jeopardy.
A Labour spokesman said: “Whether it’s teaming up with the Tories to oppose new homes in Enfield, or their leader Zack Polanski misleading the public over his failure to pay council tax – the Greens are showing they won't do the right thing for Londoners.
“Labour will continue to work hard and deliver for residents across the capital. Because the Greens simply aren’t up to the task.”