[6] The scheme was shelved as part of the conditions for emergency COVID-19 funding worth £1.8 billion between the government and Transport for London (TfL) announced on 1 November 2020.

[23] The greatest level of opposition to the principle of Crossrail 2 came from the residents of Kensington and Chelsea, the only area with more than 5% of respondents (16%) who strongly opposed the scheme.

[26] In October 2015, the route proposal was changed in three ways: In January 2016, Surrey County Council published a detailed report lobbying for TfL to consider extending branches to Dorking and Woking.

[31] In the 2017 Autumn Budget, the Treasury said only that it will "continue to work with Transport for London on developing fair and affordable plans for Crossrail 2, including through an independent review of funding and financing".

[32] On 2 March 2018, the UK's Transport Secretary, who represents a seat centred on a prospective terminus of one of the branch lines (Epsom and Ewell), announced Mike Gerrard would lead the Treasury's required Independent Affordability Review, which is expected to conclude in the summer of 2018.

In 1995, an alternative Express Metro plan was put forward that would utilise more existing track, have fewer stations and be built to National Rail standards.

It would take one of three routes from East Putney on the District line to Victoria; either Putney Bridge, Parsons Green and Chelsea or King's Road as in the original safeguarded plan; or to Wandsworth Town and Clapham Junction and then via Chelsea Harbour and King's Road or via Battersea.

The 1991 safeguarding also included a spur south of Victoria across the river to Battersea Park, for stabling trains and to access a riverside tunnelling site.

The London East West Study in 2000 considered Crossrail, the Chelsea–Hackney line and a combination of the two, from Wimbledon to Tottenham Court Road and then to Liverpool Street.

[42] Of the three routes proposed for south-west London the Royal Borough of Kensington and Chelsea initially favoured one going south via Imperial Wharf to Clapham Junction, but now supports the takeover of the District line's Wimbledon branch.

It linked the District line's Wimbledon branch with the Central line's Epping branch via Parsons Green, Chelsea, Sloane Square, Victoria, Piccadilly Circus, Tottenham Court Road, King's Cross St Pancras, Angel, Essex Road, Dalston Junction, Hackney Central, Homerton and Leytonstone.

[45] TfL responded by releasing its preferred options – an automatic metro and a regional scheme:[46] In July 2015, Surrey County Council commissioned a study to propose in detail and with cost-benefits analysed proposals, services from Surbiton as far as the main line stop of Woking (and whether or not to serve directly the four main intervening stations).

[47] Options explored were the re-routing trains so as not to terminate at Waterloo and creative timetabling plans to add capacity to the South West Main Line such as the option of moving trains onto the lighter-used New Guildford Line which runs between Surbiton and Guildford, looking at more semi-fast stopping patterns enabled as well once the Waterloo bottleneck is lifted.

[50] In March 2016, the National Infrastructure Commission said that Crossrail 2 should be taken forward "as a priority" and recommended that a bill should pass through Parliament by 2019 with the line opening by 2033.

[53][54] The current mayor of London, Sadiq Khan, also supports the proposal,[55] as does the former Secretary of State for Transport Chris Grayling.

[59][60] During the Elizabeth line opening ceremony in May 2022, Boris Johnson said that "the government should be 'getting on with' building Crossrail 2", however he also clarified that the business case will need to be written and put forward by Transport for London.

[66] There was only a short interval between the announcements of the confirmation of continued government support for Crossrail 2 in 2017, and of the scaling back of proposed railway electrification projects which would particularly benefit Wales and Northern England.

Greater Manchester mayor Andy Burnham considered that the in-principle spending decision gives undue and unbalanced priority to London and South East England over other parts of the United Kingdom.