The new north-south service will include a new 'first class dining' service
The green light has been given for a new faster train service between north and south Wales.
The new Arriva Trains Wales North South Premier Service will run from 15 December between Holyhead and Cardiff.
But Clwyd South AM Karen Sinclair protested because the service, cutting the five-hour journey by 30 minutes, will not link directly to Wrexham.
The Welsh Assembly Government has also announced a new half-hourly Cardiff to Merthyr Tydfil service for May 2009.
The Holyhead-Cardiff service will arrive in the capital by 1000 BST each day and depart at 1620 BST.
Ms Sinclair said the assembly government should rethink its plans, which she called "bad news for my constituents".
"Wrexham and the surrounding area is the largest conurbation in north Wales and merely 'linking-in' the service to Shrewsbury via another train is simply not good enough.
"North east Wales is an important hub of the Welsh economy, but we need the assembly government to back this up with actions and not just words.
"We have a subsidised an air link to north west Wales, but north east Wales also needs a high speed public transport service to Cardiff that runs directly through the town."
Deputy First Minister Ieuan Wyn Jones said the new north-south service would mean passengers would be able to travel between Bangor and Cardiff in under four hours.
Initially, the new service will be routed via Crewe rather than Wrexham as Network Rail is currently unable to offer a line from Holyhead to Cardiff via the town which will arrive in the capital before 1000 BST.
More to come
"This service will make train travel between the north and south of our country a practical and attractive alternative to taking the car - expanding choice, uniting the nation and encouraging sustainable transport options," said Mr Jones.
"I have decided to start the new service as soon as possible, with the service going via Crewe, than wait for a train path through Wrexham which may not be available for some time.
"I emphasise that this service is the first of its kind - not the last."
He added that the assembly government would seek to develop the route at the earliest opportunity, including routing via Wrexham and examining the case for an early south-north return service.
Anglesey council leader, Phil Fowlie welcomed the announcement on the new Holyhead to Cardiff rail link.
"This is very good news for Anglesey and north west Wales as it makes train travel between north and south a viable option," he said.
"Following the success of the air route between Valley and Cardiff this strengthens north-south links even further," he added.
Arriva Trains Wales commercial director Mike Bagshaw added: "We are currently making preparations to Arriva Trains Wales' own coaches and providing route learning for train crew so that we can achieve a December timetable introduction."
The new Cardiff to Merthyr line is timetabled to start in May next year following the completion of improvements and signalling at Abercynon and on the Merthyr branch line.
Mr Jones said the route was great news for the valleys and underlined the assembly government's commitment to making the whole region an attractive location for people to live and work in.