The assembly government's sports minister has been accused of snubbing an event to showcase Welsh sport.
The dinner was held on the eve of the Euro 2012 announcement
Labour's Alun Pugh, in his capacity as sports minister, was unable to address a dinner held in Cardiff ahead of the announcement of the host of Euro 2012.
Labour said Mr Pugh could not leave his constituency campaign for a whole day.
The Conservatives said it showed a "lack of judgement", the Lib Dems said it was a "poor show" and Plaid Cymru said it was an "embarrassment".
The dinner at Cardiff's Hilton hotel was held on the eve of European football body Uefa's announcement in the city of the hosts of the 2012 European Championships.
The event, arranged by the Football Association of Wales (FAW), was attended by heads of state and dignitaries from across Europe.
Uefa invited the assembly government to host the event and welcome the guests to Wales.
On Monday, the FAW was informed that Mr Pugh had to drop out.
The FAW then say that the indication came from Rhodri Morgan's office that he could possibly attend in his place, although Labour denies this.
However, on Tuesday morning the FAW were informed that Mr Morgan couldn't come either, and Labour's John Griffiths, invited to attend as deputy health minister, would speak.
FAW general secretary, David Collins, said: "Mr Griffiths was excellent and made everybody feel welcome.
"He gave a very nice speech but it is a little disappointing considering there were so many heads of state in one place that we didn't have somebody like the first minister or somebody at a ministerial level.
"When you're doing everything to portray Wales and its capital city Cardiff in the best of lights, one was a little disappointed."
'Proud to attend'
Alun Pugh is fighting to keep his marginal Clwyd West seat.
A spokesperson for the Labour Party said Mr Pugh had originally accepted the invitation but he had decided on the day before the event that at this stage of the election campaign, he could not leave his constituency for a whole day.
The spokesperson also said that the FAW had then asked whether Rhodri Morgan could attend, but he too was already campaigning in north Wales, and would not have been able to make it back to Cardiff in time.
The spokesperson added: "John Griffiths attended in his ministerial capacity on behalf of the cabinet.
"We were proud to attend this event, and this was no slight to the Football Association of Wales nor to those attending."
Opposition parties criticised Mr Pugh's decision not to attend.
Welsh Lib Dem sports spokesperson Eleanor Burnham said: "It's a poor show that the minister for sport has missed such an important international event.
Alun Pugh was unable to leave consituency campaigning
"This should have been an ideal occasion to lobby the decision makers of European football about bringing more major football finals to our national stadium."
The leader of the Welsh Conservatives in the assembly, Nick Bourne, said: "This ranks alongside the First Minister's failure to attend the D-Day commemorations in 2004 as an example of how Labour ministers are letting Wales down.
"It is not every day your country gets to host a ceremony to announce the winning bid for one of the world's largest sporting events.
"Alun Pugh's decision is a matter of national embarrassment."
A Plaid Cymru spokesperson added: "It is disgraceful that the Welsh minister for sport fails to turn up to a dinner to mark the most high profile and important announcements in this year's sporting calendar.
"We need political leadership that we can be proud of not one that makes us cringe with embarrassment."