A report has emerged which shows the south Wales valleys has fared worse than any other part of the UK following the demise of the coal industry.
The State of the Coalfields study has shown the south Wales valleys compares badly to other coalfield areas of the UK such as Durham and Yorkshire in terms of job prospects and the health of local people.
Plaid Cymru Leader Leanne Wood said the report was an "appalling legacy" for Labour politicians as well as Tory and Liberal Democrat politicians.
The AM for South Wales Central said: "This report confirms the extent to which Wales' former coalfield areas have been allowed to decline following the pit closures of the 1980s.
"This a damning indictment of countless Westminster Governments led by both the Tories and by Labour. It also shows the consequences of one-party domination as Wales has seen over the past few generations.
"Labour in Wales could and should have made real inroads into tackling the problems faced by people in the former coalfield areas of Wales. Lack of ambition, combined with complacency and taking people's votes for granted, has meant the downward spiral has not been arrested.
"The youth unemployment rate of more than 40% in my home valley, the Rhondda, which is the highest in Wales, is an appalling legacy for Labour politicians in local government, in Westminster and in Cardiff Bay.
"Austerity from the Tory/Liberal Democrat coalition in Westminster is not helping but the difficulties in the valleys stem from many decades of inaction. And it's ongoing.
"Our Assembly has very few job creating levers, yet the Labour government in Cardiff Bay rejects opportunities to get them.
"Wales needs a new government. The Party of Wales can provide the ambition and drive needed to offer people hope that this grim economic situation can be turned around. Plaid Cymru wants to see Wales become a prosperous, healthy nation.
"We want to create good jobs. We can only put our plans into action if people from all parts of Wales get behind us and back us."
Shelley Rees-Owen, Plaid Cymru councillor for the Pentre and the party’s Westminster candidate for the Rhondda, said: "It is plain to see from anyone living in the valleys that these are tough times. The so-called recovery that we are supposedly experiencing has not reached the valleys, if it has reached Wales at all.
"On top of that, in Rhondda Cynon Taf we are experiencing some of the harshest and most callous local authority cuts - targeting the young, the elderly, the infirm and the disabled – and they are all being delivered by a Labour administration.
"It is true to say that the area has yet to recover from the pit closures of the 1980s.
"The decline of manufacturing in the last 20 years has also seen a lot of jobs lost to the area. The Labour Westminster Government between 1997 and 2010 must take their fair share of blame for neglecting the area.
"At a time when you cannot separate Labour from the Tories and the Liberal Democrats, an alternative political voice is needed.
"The only political party with the policies, boldness and indeed freedom from Westminster influence – which always takes precedence with other political parties – is Plaid Cymru."