All aboard: Now that Labour has decided to support a referendum on Europe, the 'pro' camp needs to get its act together

As well she might, Labour’s acting leader, Harriet Harman, looked a bit sheepish on The Andrew Marr Show as she executed her U-turn on the Europe referendum. After all, as a loyal deputy to Ed Miliband, she has spent the past few months wandering around the country in a pink van telling us it would be a disaster. Her reason for this change of policy was that Labour wouldn’t be able to stop the Conservatives getting the legislation through Parliament anyway. Unspoken subtext: “So why bother?” That does not bode well for the spirited, principled opposition the country expects from Ms Harman’s party. She and Mr Miliband argued that a referendum would create uncertainty and damage private investment, and so it will.

Given that this distracting and risky referendum is indeed now sure to arrive, Labour and all the other pro-EU forces need to start coalescing. It is time for the various business groups to put aside their relatively minor differences, and this they seem prepared to do, as this newspaper reported last week. British Influence, Business for New Europe and the European Movement are looking to launch their umbrella group in September. That should help them steal a march on the No campaigners.The next step, following the party conferences, should be for the political arm of this movement to be solidified.

As with the Labour Party, this grouping will need a leader, or at least a figurehead, who is likely to inspire and persuade alienated voters, but not provoke undue partisan rancour. Though either Miliband brother could be plausible, the former foreign secretary David Miliband is mercifully free from association with the recent political scene. If he could summon up the energy, Alan Johnson would also be a popular choice.

The pro-Europe campaign will have the better part of the talent, the funding, celeb backers and slick marketing. It will, though, need powerful arguments, too. The last time we had a national vote, in 1975, Britain was bottom of the growth league, was the “sick man of Europe”, and remaining in the then fast-growing, dynamic European Economic Community was recognised to be at least part of the answer to a distressing long-term UK economic decline. The alternative was the old Commonwealth and the Soviet bloc.

Now, as Greece’s interminable debt crisis reminds us, the EU is no longer a global economic powerhouse, and desperately needs reform, while the Brics leave it behind in the global race. Pro-Europeans will need to demonstrate why Europe still matters as a huge market, how it can be made more globally competitive, and why trading with Spain, Germany and Bulgaria does not stop us from exporting to India, China and Indonesia. Our trade, in other words, is not a zero-sum game.

Proponents of Europe will also need to be more convincing on the question of immigration from Eastern Europe, if we are to see a resounding vote to stay in. Seeing well-fed bankers, Brussels commissioners and business people on TV lecturing those on the minimum wage about the merits of unrestricted immigration from the Balkans will not be an attractive or politically persuasive sight. The anti campaign will be Ukip writ large; an anti-establishment insurgency posing for the people – working people. David Cameron will not win the argument if all he can do is say that Romanian benefits tourists will be kept out.

The truth is that hardly anyone outside the Tory back benches really wanted a European referendum, and that the Ukip vote was much more a cry for economic help from depressed towns and cities than a genuine desire to tear up our relationship with the EU. Now that it is coming, it will not be enough to just win it: it has to be won big by the pro-Europe camp. And the more successful a cross-party campaign, the more chance of developing further in the next few years a progressive wider opposition to the Government as Labour and Liberal Democrat leaders work together with business and the unions. Provided we see a solid Yes vote, the referendum experience may not be all bad at all.