MP for Cambridge, Daniel Zeichner has signed an open letter to Labour leader Jeremy Corbyn calling for the party to change policy and back a change in the UK’s electoral system.

The letter, signed by Zeichner and six Labour Party colleagues, including deputy leadership candidate Ben Bradshaw and former Shadow Business Secretary Chuka Umunna, calls for the adoption of a “truly democratic electoral system,” and requests a meeting “to discuss how we can support the Labour Party as it develops its position on the matter.”

Corbyn has, in the past, expressed a willingness to consider electoral reform, but has stopped short of actively endorsing the adoption of Proportional Representation (PR). Shadow Chancellor John McDonnell today declared his support for electoral reform, arguing that “when Parliament fails to represent the people so flagrantly, it risks ceasing to be legitimate.”

The letter was published ahead of today’s “Demo for Democracy” protest in Westminster, which has received cross-party support, and was attended by Green Party leader Natalie Bennett, UKIP Deputy Chair Diane James, Liberal Democrat President Baroness Brinton, and Guardian columnist Owen Jones.

Scottish National Party MP, Stewart McDonald, who also spoke at the demonstration, praised the Make Votes Matter coalition, and highlighted the “huge appetite” for change.

Zeichner has been a long standing supporter of reform to the voting system – in an interview with Varsity prior to last year’s general election, Zeichner said he considered the adoption of PR to be “part of changing Britain, moving into a 21st-century democracy.”

When a Private Member’s Bill was brought before Parliament in December 2015 by Labour Party colleague Jonathan Reynolds, then Shadow Transport Minister, Zeichner was one of just twenty-seven MPs to back the adoption of the Additional Member System (AMS), the version of PR used in this week’s Scottish Parliament, Welsh Assembly, and London Assembly elections.

Support for a change to the electoral system has historically been disproportionately high in Cambridge. In the 2011 referendum on the Alternative Vote (AV) system, Cambridge was one of just ten counting areas to vote yes to the replacement of First Past the Post, voting 54.3 per cent in favour against a national trend of 67.9 per cent against.