Edward McMillan-Scott: The Tories must shun the wilder fringes

The Irish "yes" to the Lisbon Treaty leaves the Conservative leadership at this week's conference in Manchester with a dilemma. This is because their latest pledge for an incoming Tory government – that if all countries had ratified there would be no referendum – is being challenged by Euro-sceptics. David Cameron will be right to resist them: they have done much damage already to the party's international reputation.

The sceptics point to the second sentence in June's Conservative European election manifesto, which states "if the constitution is already in force by then, we have made it clear that in our view political integration in the EU would have gone too far, the treaty would lack democratic legitimacy, and we would not let matters rest there".

The Euro-sceptic media and anti-EU campaigners such as Dan Hannan MEP have been calling for a referendum willy-nilly. Open Europe is now urging a separate back-stop referendum – on EU reform. No doubt the conference fringe will be throbbing with passionate intensity but it is the platform which decides policy: can the centre hold?

Pressed last week on what he means by "we will not let matters rest", Cameron said that if the treaty is through then a new set of circumstances apply "and I will address those at the time". This can be read as moving any decision on a referendum forward to his general election manifesto, and months of speculation about his intentions.

I shall not be in Manchester, but representing the European Parliament at a conference in Stockholm – Sweden holds the six-month rotating EU presidency – of senior parliamentarians from all the EU's chambers, every one of which has examined the treaty, debated it, and approved it. The Irish Dail and Senate have still to approve it formally.

Whatever its defects, the treaty gives national parliaments a decisive and direct say for the first time in EU decision-making. This democratic partnership with the European Parliament – whose powers are also enhanced – offers a real chance of EU reform and parliamentary control of the union's bureaucratic machinery.

I shall be representing the European Parliament as its first independent vice-president, not chosen by party bosses. Last month I lost the whip and was expelled from the Conservative Party after 42 years. This vengeful and fruitless move occurred after I stood and won re-election as vice-president against Michal Kaminski, a Polish MEP with extremist links from Cameron's new European Conservatives and Reformists (ECR) group.

At the inaugural meeting of the ECR group, I stated that I was uncomfortable and that if anti-federalism was its motive, MEPs had no powers in this. I also warned that if the ECR contained MEPs with links to extremist groups "like Poland's National Revival (a neo-Nazi movement)" there would be difficulties. It turned out that Kaminski had been in National Revival, but he tried to cover it up.

In my view, Cameron was badly advised by Europhobes like Hannan (a friend of Kaminski's, to my knowledge, for several years), who in turn was used by the Pole to make his own rather repellent party respectable. The negotiations were conducted, understandably, in secret. The ECR does no credit to Cameron. One consequence is that the victorious German Chancellor Angela Merkel is now withdrawing links with the Tory Party.

There will be relief in most European capitals that the Lisbon Treaty is now more or less home and dry. However, it must still be signed by the Czech and Polish presidents. The Euro-sceptic Czech Vaclav Klaus is under pressure not to fulfil his earlier commitment to sign once the Irish had voted yes. His ODS party, one of Cameron's ECR partners (despite its denial of climate change) was split in the final vote in the Czech senate. The Polish president and his former spin-doctor, the same Michal Kaminski, are in favour of the Treaty. We look forward to Kaminski's appearance in Manchester.

There have been referrals of the treaty to the Czech constitutional court with the later agreement, designed to satisfy Irish concerns, attached to it. These filibusters are intended to delay the process in the hope that a Conservative government will be elected in the UK before a ruling.

Cameron's pledge, during his leadership election, to pull Tory MEPs out of their association with the Christian Democrat/Conservative European Peoples Party (EPP) group mystified many. His rival, David Davis, a former Europe minister would not give it.

In 1999, while leader of the Tory MEPs, I, along with William Hague, secured an even stronger independent status alongside the EPP group. Conservative MEPs since then have been free to advocate their own vision of Europe's future and to follow their own whip. But now, by leaving the mainstream and joining the extreme, the Conservatives have moved from being at the heart of Europe's centre right to its wilder fringes – a gift, as their conference speeches have shown, to the Lib Dems and Labour.

EPP meetings before EU summits were attended by William Hague, Iain Duncan Smith and Michael Howard. Each Tory leader considered and renounced abandoning the EPP link. It currently brings together 14 heads of government, providing an opportunity to maximise leverage on the international stage. Right now, instead of allowing Tony Blair to become putative president, Cameron should be promoting – with the support of the centre-right – Chris Patten, a Tory experienced and well-known in EU circles, as head of EU foreign policy.

As prime minister, Cameron will discover the advantage of having friends and allies across the Europe. To achieve his agenda on EU reform, an open Europe and climate change, Britain cannot afford to be isolated. I am a Conservative internationalist and I want Britain to lead in Europe, not leave it. In that, I have many friends in the Conservative Party too.

Edward McMillan-Scott MEP is a vice-president of the European Parliament. He sits as an independent