The UK parliament will hold a debate on dropping oil, gas and other fossil fuel stocks from its pension fund on Wednesday 22 May, as MPs advocating divestment bid to win more colleagues to their cause.

The initiative, spearheaded by Liberal Democrat MP Ed Davey and Green MP Caroline Lucas, has gained pledges of support from 221 serving MPs — one-third of the total 650 — and 28 former MPs who still have savings in the £730m Parliamentary Contributory Pension Fund.