The CEE Bill was developed by scientists, academics and lawyers, along with members of the Big Ask campaign, which led to the Climate Change Act back in 2008. The campaign for the CEE Bill was launched in August 2020 and introduced in Parliament the following month as a Private Members’ Bill.


The Bill gained the maximum support of cosponsors with 12 members of parliament (MPs) from seven different parties. Cosponsors are MPs who put their name to a Bill in order to present it in Parliament. Caroline Lucas (Green Party) is the principal sponsor of the CEE Bill and the 11 other cosponsors are: Alan Brown (SNP), Stephen Farry (Alliance), Claire Hanna (SDP), Wera Hobhouse (Lib Dems), Ben Lake (Plaid Cymru), Clive Lewis (Labour), Liz Saville Roberts (Plaid Cymru), Tommy Sheppard (SNP), Alex Sobel (Labour), Zarah Sultana (Labour) and Nadia Whittome (Labour). On 2 September Caroline Lucas introduced the CEE Bill in the House of Commons for the first time.