The Severn bridges will revert to public ownership on 8 January allowing tolls to be scrapped by the end of 2018, the UK government has confirmed.
Monmouth Conservative MP David Davies said he was "very pleased" with the news, which he received in a letter from Transport Minister Jesse Norman.
Mr Davies said it proved the pledge was "not some wild manifesto promise".
Welsh Secretary Alun Cairns has described the tolls as a "psychological barrier" to doing business in Wales.
The first Severn Bridge, which opened in 1966 under public ownership, was transferred to Severn River Crossings plc as part of the agreement under which the company built and financed the second crossing, which opened in 1996.
Both bridges would be returned to public ownership once construction and maintenance costs had been recovered from the collection of tolls.
Mr Davies had written to the Department for Transport on behalf of a constituent, seeking confirmation of the date of transfer.
Mr Norman replied saying: "I am pleased to confirm that the bridges will revert to public ownership on 8 January 2018 and that all tolls will end at the Severn Crossings by the 31 December 2018."
The Monmouth MP said: "I'm very pleased with it - it's the confirmation everyone had been expecting and not some wild manifesto promise.
"It's going to be carried out in the timescale promised."
Mr Davies said he understood there were some unexpected additional maintenance costs to be covered which meant that the tolls would not be lifted immediately.
When asked to comment, the Department for Transport referred to the announcement in July, when Transport Secretary Chris Grayling said abolishing the tolls would "drive economic growth for businesses in Wales and the South West [of England] and further strengthen the bond between our two great countries".
The Welsh Government has also been asked for a response.