Crossrail 2 is a proposed rail route in South East England, running from nine stations in Surrey to three in Hertfordshire, providing a new North–South rail link across Greater London. It would connect the South West Main Line to the West Anglia Main Line, via Victoria and King's Cross St Pancras. It is intended to alleviate severe overcrowding that would otherwise occur on commuter rail routes into Central London by the 2030s. Should permission be granted, construction is expected to start around 2023, with the new line opening from the early 2030s. The project's cost has been estimated at £31.2 billion. Boris Johnson, when Mayor of London, called for the line to be called the "Churchill line", after Winston Churchill.