Senior Tory figures are understood to be in favour of a island airport in the Thames Estuary, which would cost up to £50bn

Plans for a major hub airport in the Thames Estuary have received the backing of the Downing Street and Chancellor George Osborne, the Financial Times reports.

The airport, proposed by architects Foster and Partners and designers Halcrow, would act as a hub to the whole UK with high speed rail links to major ports, Bristol and northern cities.

The estimated cost of the project is between £40bn and £50bn. But according to the Financial Times’ sources Osborne has switched from sceptic to supporter of the scheme in recent weeks.

The idea is already understood to be popular among the prime minister’s advisors.

Senior Tory figures are also said to be favour the idea of an airport in the Thames estuary but are undecided between Foster and Partners’ plans and a previous version of the scheme put forward by Mayor of London Boris Johnson, the paper reports.