So it looks like he was just in it for the ride then! I don't blame the PM, out of sheer decency he was trying to use the best brains at his disposal and sometimes that means looking outside the confines of party politics. But Lord Jones should have known better.When you are a government minister you represent the government as a whole, not just one tiny part of it. Any arguments, disagreements etc.. which occur, which is natural, should be conducted in private.
In any case, if he runs along to the Tories' now he will look a bit silly, in fact so would the Tories, which wouldn't be difficult.