Transport for London (TfL) has indicated the Bakerloo Line Extension could begin running in 2040, subject to funding approval.
TfL papers have revealed construction of the scheme could begin in 2030 although this would still rely on obtaining government grants.
The report also said the predicted cost of the Bakerloo Line extension had spiralled to between £5 billion and £8 billion at 2023 prices.
However, this is only slightly more than an estimated £7.9 billion which TfL has long cited as a possible figure.
The TfL paper reads: “The current EFC (Estimated Financial Cost) is between £5-8bn (2023 prices) and the scheme could feasibly begin construction from 2030 subject to funding.”
The Bakerloo line extension would go from Elephant and Castle station to Lewisham station and see three new tube stops built.
These would be called Burgess Park, where the big Tesco currently is, Old Kent Road, on the current Lidl site, and New Cross Gate, at the big Sainsbury’s.
The extension is key to the development of the Old Kent Road area, where Southwark Council hopes to build 20,000 new homes, including at least 5,000 social rent properties, by 2038.
However, TfL must navigate significant stumbling blocks before the project gets started.
As part of a 2022 bail-out, £1.2 billion of government funding supported almost £3.6 billion of major transport projects in the capital. But this fell well short of the possible £8 billion needed for the extension.
In December, the Department for Transport (DfT) approved a funding package worth £250M for TfL to cover the 2024/2025 tax year.
TfL doesn’t need to fund the entire project. Some money would come from local authorities like Southwark, and developers would pay through a community infrastructure levy (CIL).