Since 2014 there have been no confirmed plans to connect HS2 to HS1, meaning that Regional Eurostar services are no longer being considered. The prospect of an HS1-HS2 link was revived in 2018 when a proposal was put forward by engineering consultancy Expedition Engineering for HS4Air, a high-speed railway line that would create a link between the two lines across southern England. By running south of Greater London, it would also connect Heathrow and Gatwick Airports. This scheme remains at the proposal stage and has not been officially endorsed by government.