Caroline Lucas will step down as co-leader of the Green Party in September, saying she would like more of the party’s talent to be showcased.

Lucas, the party’s sole MP, has represented Brighton Pavilion in the House of Commons since 2010 and returned for a second spell as leader on a joint ticket with Jonathan Bartley in 2016.

In a piece for The Guardian, the former MEP said she had faith that a new leadership team “will step up to the challenge that our increasingly febrile times present”.

Under the rules of the party, leaders are elected to serve a two-year term, with the Lucas-Bartley joint ticket securing more than 86% of the vote to succeed Natalie Bennett.

She wrote: “I won’t be seeking nominations to be a candidate in this year’s leadership election, when the process starts on Friday, but instead will be focusing even more on work in Parliament and in my Brighton constituency.

“I believe that Jonathan and I have shown the power of working together, since we became joint Green Party leaders in September 2016, and it’s now time for me to show the power of letting go.”

Bartley said it had been an “absolute blast” working with Lucas.

The Green Party’s vote share dropped 2% at the snap general election in 2017, having been squeezed by a Labour party moving to the left.

But the party did make gains in local elections earlier this month, where the party won 39 council seats – an increase of eight.

Speaking at the time, Lucas said the Greens have overtaken UKIP and become the fourth party in English local government.

“The Green Party has taken a significant step forward with just a fraction of the resources of the bigger parties. We are now established as one of the four major English parties – and an electoral force right across the nation,” she said.

Nominations for the Green Party leadership open on Friday and the new leadership team will be announced in September.