The funding announcement comes ahead of the submission of a Development Consent Order (DCO) to the Government in July.
All nationally-significant infrastructure projects require a DCO before they can progress.
MetroWest Phase 1 is being led by North Somerset Council and the West of England Combined Authority on behalf of South Gloucestershire, Bristol City and Bath and North East Somerset councils.
As well as reopening the Portishead Rail branch line, with two new stations at Portishead and at Pill, this MetroWest scheme also includes vital improvements to passenger services along the Severn Beach and Bristol to Bath Lines.
Colin Medus, Head of Transport and Infrastructure at North Somerset Council said: “The Portishead Rail scheme is a nationally-significant project that will open-up the rail network to thousands of people across the region and will help relieve congestion during the rush hour periods.
“We are committed to investing in the infrastructure of our area and this Government funding is the news we have been waiting for. MetroWest Phase 1 is firmly on track for delivering rail services fit for the future of our region.”
For more information about the MetroWest project, visit our MetroWest page.