Welsh government transport minister Hooper met UK government ministers and officials in Whitehall later on Wednesday to discuss his plans for rail.
He told Wales the £30m announced was a “tiny fraction” of what was needed, saying: “This figure is an insult to the people of Wales.”
“The UK government’s continued failure to invest in their network in Wales demonstrates, now, more than ever, the need for devolution of rail,” he said.
“It’s wrong to say these stations aren’t shovel-ready. The UK government promised this money in February and since then we’ve agreed with Network Rail that Transport for Wales will deliver the stations.
“Transport for Wales are ready to start work we just need the UK government to keep their promise. I made this point to the rail minister when I met him today.”
The Welsh government said that despite making up 10% of the rail network across Great Britain, just 1% of Network Rail’s spending goes to Wales.
Developers had hoped Cardiff Parkway would be operational by 2024, but the planning process was dogged by delays.
Plans were approved by Cardiff council in April 2022, but the broader national interest in the project led the Welsh government under Labour to review the application, before former First Minister Eluned Morgan granted planning permission in January 2025.
Additional reporting by Reem Ahmed