Graham is to deliver the first £100m slice of Cardiff’s eagerly awaited Crossrail project.

The contractor, which has offices in England, Scotland and Ireland, secured a deal to carry out detailed design and build on phase 1a of the tramway.

The first phase will develop the link between Cardiff Central and Cardiff Bay railway stations, which are about 1 mile apart.

Funding for this section has been secured, with the UK and Welsh governments each pledging £50m.

Subject to further cash being raised, phase 1b would see the line extended to Pierhead Street in the bay.

Further stages could eventually follow. Plans set out in 2021 suggested a £1bn initiative could link Creigiau to the west of the city with Newport Road in the east.

Graham has been appointed to phase one under an early contractor involvement deal that will see the firm work with the city council and Transport for Wales up front to manage costs.

As well as the infrastructure itself, and a new platform at Cardiff Central, works will remodel the highway network around Callaghan Square in the bay.

New public realm will be developed in front of the square, with a segregated cycleway and changes to access arrangements for general traffic through Bute Terrace and Lower St Mary Street in the city centre.

Phase 1b would see roads reworked around the Flourish and Pierhead Street to allow for a tram track extension. This part of the scheme would also include improved facilities for pedestrians and cyclists.

A Cardiff Council spokesperson said: “It is great news that we have had the funding confirmed from both the UK and Welsh governments. This means that the detailed work can now begin.”

He said the local authority would plan with Graham how to maximise the social value of the works.

“The Cardiff Crossrail is an ambitious plan to deliver Cardiff’s new tram transport system, which will eventually run from the north-west of the city all the way to the east, connecting with the proposed Parkway Station.

“Following further funding opportunities, we intend to provide a cross-city tram service that is affordable and reliable for the public to use, and to connect some of Cardiff’s poorest communities to the rail network for the first time.

“To start this process, the first phase of the scheme must be built between Cardiff Central and Cardiff Bay.”

Detailed design is set to be completed by next autumn with work scheduled to start on site by the end of next year.

The spokesperson said: “Under the current programme of works, the construction could be complete by early 2028, with trams running on the track from later that year.”