Corbyn’s intervention is a start... but he must go further

As if the prime minister doesn't have enough problems already Labour has finally been roused on Brexit.

Smelling blood from Number 10, Jeremy Corbyn has ramped up the pressure on the PM – but he still has a long way to go.

Sir Keir Starmer's finger prints were all over Corbyn's speech and without his influence it is unlikely this keynote would have ever been made.

It appears May's increasingly wobbly position – Brexiteers and Remainers squabbling inside the cabinet and hard-liners firing off their redlines on leaving the EU – has prompted Corbyn to act. There is every possibility that Tory rebels will vote along with Labour over amendments to the EU (Withdrawal) Bill. This could prove fatal for May's premiership.

But Corbyn and Labour must now ensure their new, stronger position is just the starting point.

The speech was wide-ranging and critics will rightly say it amounted to a wish-list. We need more detail and more realism – if the government's position is to have our 'cake and eat it' Labour's must not become having a different, tastier cake and eating it.

Now is not the time for promises that can never be delivered. Britain deserves to be told the truth – facts were in short supply during the referendum campaign and Labour must not fall into the trap of promising the world when it cannot deliver.

After the speech Corbyn was accused of playing politics by taking so long to make his Brexit intervention. That is almost certainly true. The belief that the Tories should own Brexit has been pervasive inside Labour.

The Opposition is obliged to tackle the government – that it has taken this long should not be forgotten. Labour must now go for May full-throttle in a bid to shape Brexit for the good of the country.