Plaid should avoid joining a "Dark Rainbow" opposition.

What can we make of  Plaid Cymru AM Adam Price  announcement that Opposition parties in the assembly are entering a "new phase" of co-operation in scrutinising Welsh Government,

Mr Price said the opposition will soon establish a "common front" on a range of issues.
The Labour-led government has a working majority in the assembly but recently lost three opposition-day votes.
The leader of the Welsh Tories last month said he wanted to work with other parties.
The UKIP Wales leader Neil Hamilton said that he was prepared to co-operate even if it meant he would 

"vote through things in which fundamentally I don't believe, but which are better than the other alternatives".

Which is interesting  but does in contrast Mr Price claim that: ]

"Where there is legitimate reason to challenge the Welsh Government, not opposition for opposition's sake, but where we would be failing to do our job if we weren't to do it, then I think we will see increasingly... a common front on a whole range of issues."

 Welsh Tory leader Andrew RT Davies says his door is still open to any party who wants to work with the Conservatives.

"I don't have any ideological reasons why I cannot work with other parties in this institution, because to me the ideological reason why Wales sadly hasn't delivered in the first 20 years of devolution is the Labour Party," .

Many Plaid supporters   may be  worried that Plaid are seeking to form some kind of "Dark Rainbow"  coalition in opposition  with the Tories and Ukip.

Though it seems Adam Price hopes that Plaid and the Welsh Conservatives could work together over  issue like the proposed M4 relief road.
His theory could be put to the test on Wednesday during a Plaid-sponsored debate on the M4 relief road, calling for an assembly vote on the financing of the project once the public inquiry concludes.
Mr Price said that while his party has a different policy to the Tories, the parties "possibly" both agree that the assembly should have a vote following the end of the inquiry.
He added that the two parties "may find common cause with some rebel members of the government backbench as well". 

Some Labour backbenchers are known to oppose the M4 relief road project.
Labour won 29 seats at the last assembly election - leaving it short of a majority.
Despite adopting two other non-Labour AMs into the government, absences on the government side meant it lost opposition votes in January.

But it shows a major problem for Plaid

Labour have led the Assembly since its inception and it seems that the only way to replace   them is some kind of "Dark Rainbow" coalition with the Tories and another party,

There are those who argue that going  into opposition would reinvigorate Labour and see them coming out of the sort of lethargy that has been the impression of Carwyn Jones's government.

But the evidence from Scotland where they have lost three elections in a row is that they will still be little more than a branch of the London HQ.

Another example of problems of Parties in opposition can also be gleamed from the latest Holyrood budget .

As the New Statesman points out
 

The responses were predictable – the Tory Opposition argued that the block grant from Westminster is sufficient and that the tax rises should therefore not be blamed on austerity, but on SNP policy choices and its failure to grow the economy. It is certainly true that the economic forecasts published this afternoon by the Scottish Fiscal Commission make for grim reading. It predicts the economy will grow at less than 1 per cent a year until 2022, just 0.7 per cent in 2017 and 2018, rising to 1.1 per cent in the fifth and final year of the forecast. This is driven by an outlook of low productivity in Scotland over the period.

For Labour, it wasn’t enough. Their firebrand new Corbynite leader Richard Leonard was loud, red-faced and for some reason bouncing on the spot like a over-sugared toddler as he criticised the budget, leading the finance minister to remind him he was already being amplified by the microphone on his desk. Leonard accused the SNP of a lack of real radicalism in the face of continued austerity, which he says is having a serious impact on local services.

At least  Labour and the Tories are unlikely to form their own "Dark Rainbow" and the Greens seem more likely to support the minority Scottish Government for now.

Plaid may be walking into trouble if they are seen as collaborating with the Tories but  even the most ardent Corbyn supporter   can claim that Labour in government in Wales are a shinning example of socialism.

We need to replace Labour's  hegemony not only in Cardiff  Bay  but throughout Wales the problem for Plaid in particular is what they would do differently.