I was indeed a Labour Party member for quite some time- and also the Lib Dems. And I am NOT anti JC at all, nor am I afraid of the Labour Manifesto.
But we all know that the 'old guard' of the Labour Party, including JC, have always been anti Europe. And I do disagree that the opposition does not need a stance on Brexit, or anything of importance. There is clearly a split between the stance of Umuna, Starmer, Emily's outlook and open attitude to the EU, and that of JC and others. And this is not helpful.
Of course, waiting and waiting. for the right moment to genuinely 'oppose' - could be a very clever and effective stance- saying 'we respect the referendum' until it is so absolutely crystal clear that it will be vastly detrimental to the NHS, jobs, job security and conditions, the environment, and so much more- and then they could then say 'we respected the vote- but now we have to oppose it because... (see above).
As said DJ- my concerns about the Labour Party's lack of clear opposition- are different as I am not anti Labour at all, and have great respect for JC.
The NHS, social services, housing, schools, addressing poverty, and so much more - will not get the funding- and this especially in the hardest hit areas (even Grimsby now realises this). So Brexit is massively important in doing what the Labour party want to achieve (and that I agree with).