That is when the Airport Commission will decide whether to keep this option in the mix or throw it out.
The government established the Airports Commission in September 2012 to advise on the need for and location of future runway capacity. Its interim report in December 2013 set out three options – two at Heathrow and one at Gatwick – and called for further consideration of the Thames Estuary option.
Since then, promoters of shortlisted options have provided more detailed proposals to the commission. This autumn, the commission expects to decide whether or not to shortlist an estuary option, and will then undertake formal consultation on the shortlisted options.
The final report will be published in summer 2015, by which time it will be up to a new government to make any decision.