The Green Party’s first ever MP to win a seat at Westminster will be stepping down as Leader of the party in September 2012.

Caroline Lucas announced over the weekend she will not re-run for the position at the end of her second term later this year.

Ms Lucas said she wants to “broaden” the opportunities for other members of her party.

She said: “I’m hugely honoured to have served as the first Leader of the Green Party and I’m proud that during the four years of my term, we’ve moved Green politics forward to a higher level, with the Party by far the most influential it has ever been.”

During her time in office, the Green Party has seen “significant breakthroughs” nationally, breaking into new Councils in the recent local elections as well as gaining a bigger public profile during the elections for London Mayor, she said.

Ms Lucas said she now wants to focus on her role as the MP for Brighton Pavilion, as well as working more on the “political frontline, putting the Green case for change in Parliament and in all circles of national political debate.”