If British Prime Minister David Cameron is able to pursue a reform agenda in advance of a United Kingdom referendum to be held in 2017, then the role of German Chancellor Angela Merkel will be pivotal – writes Tim McNamara

An argument over a relatively small political party in Germany is threatening to fundamentally destabilise Anglo-German relations on the centre-right. At issue is the role of the party Alternative für Deutschland – or the AfD – in the European Parliament and its future relationship with British Conservatives.

Using this issue as a convenient rallying point, the British Prime Minister David Cameron’s core European Union objectives are under siege from his own party’s representatives in the European Parliament. Daniel Hannan MEP, the United Kingdom Conservative’s éminence grise, appears to be adopting a strategy that is deliberately designed to torpedo Cameron’s efforts to get German Chancellor Angela Merkel on his side. Cameron sees Merkel as a potential ally in his pursuit of the EU reform agenda that might be acceptable to his party.

Cameron’s ill-judged commitment to hold a referendum in 2017 on the UK’s EU membership – if he is still PM then – has further empowered some Tory MEPs to try to scupper any attempts to achieve his objectives. In this, they are also being cheered on by a significant number of Tory MPs at Westminster.

Hannan has astutely discerned that Merkel is bitterly opposed to the AfD attaining any political profile in the post-May 22 European Parliament. Although the AfD is only like to win six EP seats out of 98 in Germany, Merkel wishes to strangle it at birth. The AfD’s anti-euro stance threatens to split the centre-right in Germany and hence weaken Merkel’s party, the CDU.

Merkel perceives the AfD as a real threat in the future, fearing an echo of UKIP’s progress. This appeal by populists seems to resonate across the EU with them making significant progress in France, Italy, Spain, UK, Hungary and so on. With a former German business leader Hans-Olaf Henkel heading up the AfD, Merkel believes it could be a real and present danger to her party in the German federal elections in 2017.

Threats and counter-threats over the treatment of the AfD have been quietly exchanged between British Conservatives and the German CDU since last year. The leading German role in these meetings has taken by the rising star of the CDU David McAllister, who up until recently had been prime minister of Lower Saxony and is still very much a favourite of Merkel. McAllistair was recently offered the post of secretary general of Merkel’s party, the CDU, by the German chancellor herself.

McAllistair warned the Conservatives that if the AfD were allowed to join their political group in the EP, then relations between the centre-right in Berlin and London would suffer long-term damage. Cameron’s hopes of advancing a reform agenda in the EU would be severely affected.

The problem for Cameron is multi-dimensional and the actions of the British Conservatives in the EP are largely outside of his direct control. Taking this into account, the future of the Tories political group in the EP – the European Conservatives and Reformists – is also under threat and this will impact on their future decisions.

To have any significant influence in the European Parliament, any MEP has to be part of a political group. An officially recognised group must have a minimum of MEPs from 25 per cent of member states – seven to be precise – and have at least 25 members. The ECR is presently looking like it will struggle to achieve that de minimus level.

And so the Conservative MEPs and their Polish allies in the group – the Law and Justice Party – have decided to be somewhat less rigorous than in the past in their vetting of future group members. One of their key targets is the anti-Euro AfD, who they see as natural bedfellows. The twin benefits of assisting their political group to be viable in the next parliament and forcing Cameron’s hand over his reform negotiations are irresistible to the large majority of Tory MEPs, and their likely successors after the May 22 European elections.

If Cameron is able to pursue a reform agenda in advance of a UK referendum to be held in 2017, then Merkel’s role will be pivotal. The CDU’s warnings about the AfD may be simply scaremongering but can Cameron afford to gamble on this prognosis. Certainly a large majority of Conservative Eurosceptic MEPs, led by Hannan, will engage in as much mischief-making as possible in pursuit of a British exit. The fact that a small German political party such as the AfD can be the potential cause of so many ramifications among centre-right thinking in Britain eruditely speaks to the ongoing febrile – even feral – atmosphere around the EU.

Tim McNamara is head of the Peercourt consultancy firm. He was previously political editor at the European Commission