Denis Staunton: Fissures open up beneath Britain’s main parties

A few weeks before the referendum, David Cameron warned that a vote for Brexit would detonate a bomb under the British economy. But the first explosion has been felt beneath the political system, with Cameron's career in ruins, the Conservatives and Labour in the grip of vicious leadership struggles, and Scotland facing the prospect of a second independence referendum.

The divisions laid bare by the referendum, in terms of age, geography and social class, present difficulties for both main parties. Although much has been made of the one in three Labour supporters who backed Brexit, Conservatives were divided too, splitting about 60-40 in favour of Brexit. And although a little more than half of the voters backed Leave, more than two thirds of MPs backed Remain, including a slight majority of Conservatives and almost all Labour MPs.

These divisions are likely to have a major influence on Britain's approach to negotiations about its future relationship with the EU, and positions taken in the Conservative leadership contest may already have closed off some options. Frontrunner Theresa May, who backed Remain, made clear when she launched her leadership campaign on Thursday that there was no question of reversing the decision to leave the EU.

“There must be no attempts to remain inside the EU, no attempts to rejoin it through the back door, and no second referendum,” she said.

May wants Britain to retain access to the European single market but she said that could not come at the price of continuing to allow the free movement of people from the EU. Other Conservative leadership candidates have taken a similar approach, effectively closing off the option of Britain following Norway’s example of remaining part of the single market and accepting free movement of people.

"I will end free movement, introduce an Australian-style points system and bring numbers down. With my leadership, it will be delivered," Michael Gove said yesterday.

The European Economic Area agreement, which governs the economic relationship between the EU and Norway, includes a safeguard mechanism which could be used to limit immigration in some circumstances. But such an arrangement would have to be temporary or transitional and all EEA members accept the principle of free movement.

It is not only the Conservatives who are opposed to maintaining free movement of people after Brexit – Labour is adopting a similar stance. Shadow chancellor John McDonnell, a close ally of Jeremy Corbyn, stated flatly yesterday that after Britain leaves the EU, "free movement of labour and people will come to an end."

Of course, Corbyn and McDonnell will both be gone if Labour’s MPs have their way, but any alternative leader is likely to harden the party’s policy on immigration. One of Corbyn’s potential challengers, Owen Smith, has been talking in recent days about the “progressive case against freedom of movement”. And many Labour MPs are spooked by the prospect of some of their supporters who backed Brexit switching their allegiance to Ukip because of immigration.

If Corbyn wins a fresh leadership battle, the future of the Labour party itself is uncertain after 80 per cent of its MPs have expressed no confidence in their leader. And a weak or broken Labour party is likely to boost the fortunes of Ukip, increasing pressure on the government to take an uncompromising line in negotiations with the EU.

The Liberal Democrats, almost wiped out in last year’s general election, could find a new relevance following the referendum, as the only party promising to campaign to keep Britain in the EU or to re-join if Brexit goes through.

Parliament will play a role in the negotiations with Brussels, and some constitutional experts this week suggested that the prime minister will need parliamentary approval to invoke Article 50 of the EU treaty, which starts the formal exit process.

MPs will have an oversight role during the negotiations and although the House of Commons cannot veto any final agreement, it can effectively block its ratification indefinitely.

While the two main parties in England have been consumed in internal convulsions, Scotland's first minister Nicola Sturgeon has distinguished herself with a sure-footed response to the referendum. The Scottish National Party leader has promised to heed Scottish voters' wish to remain part of the EU, "particularly the single market".

The Scottish parliament this week passed legislation which could enable Sturgeon to call a second referendum on independence. And she has embarked on a charm offensive in Brussels to win support for the idea that Scotland could remain in the EU after the rest of the UK leaves it. This is problematic, not least for member states such as Spain, which are wary of anything which could encourage separatism.

Scotland’s interest, like Ireland’s, lies in Britain negotiating the closest possible relationship with the EU after Brexit. The political manoeuvrings in London this week have made such an outcome less likely.