The £900m link was brought to a “controlled pause” by Network Rail in January 2021 as a result of the impact of COVID-19 restrictions on the aviation industry raising concerns that the project may never be put into place.

[3] Theresa Villiers, the rail minister at the time, included the project in the High Level Output Statement published in 2012.

[7] In May 2018, it was reported that Network Rail intended to apply for a Development Consent Order (DCO) in 2019, and the construction would be privately financed.

[8] Before submitting this, Network Rail would present the final designs for the scheme in a series of public information events,[9] which were held in early 2020.

[10] The Department for Transport's Rail Network Enhancements Pipeline, published in October 2019, listed the project among those in an early stage of development, awaiting a "Decision to Design" and the completion of an outline business case.

[19] Another alternative scheme was the Windsor Link Railway, proposed in 2013 and rejected by the government in 2018, which would have provided both western and southern access to Heathrow.

A complementary scheme which could be developed at a later date, or alongside the Western Rail Approach, is the Heathrow Southern Railway, proposed since 2017 to provide links from the airport to the south and south-west.