It was on the manifestos for the major parties
Labour’s here https://www.theguardian.com/environment/2019/oct/13/labour-pledges-to-ban-sale-of-petrol-diesel-cars
Conservatives had already said they were banning in 2040 and such was urgent need they needed to bring it forward
Party manifesto summaries here
Election 2019: What the main parties’ manifestos say about zero-emissions transport