It's only been a day since parliament's far-right MEPs announced the creation of their new group, Europe of Nations and Freedom (ENF), but other deputies have been quick to react.
Chair of parliament's European People's Party (EPP) group Manfred Weber said, "the strengthening of Europhobes must be a wake-up call for all democrats in Europe", urging "all constructive forces in the parliament [to] close ranks and fight resolutely to bring good results in the interest of citizens".
The ENF counts 36 members so far and as parliament's smallest group is unlikely to wield any significant power when it comes to votes, however, its MEPs will now be allocated considerably more speaking time and funding compared to when they were non-attached.
Socialist group leader Gianni Pittella warned that, "at a time when EU solidarity on migration and Greece is at risk, the creation of an anti-EU xenophobic group in parliament is bad news".
He also noted that the new coalition was "a contradiction in itself: anti-Europe nationalists coming together to form a European political group in the European parliament".
ENF vice-chair Janice Atkinson was previously a member of parliament's Europe of Freedom and Direct Democracy (EFDD) group, led by United Kingdom Independence Party (Ukip) founder Nigel Farage. She was suspended from Ukip following accusations of fraud.
ENF co-chair Marine Le Pen had tried to form a group with Farage after last year's elections, but he refused to associate with her.
Alliance of Liberals and Democrats for Europe (ALDE) group deputy Catherine Bearder called Atkinson's move, "a disgraceful decision by a disgraced MEP. The people of the south east region she represents will undoubtedly be shocked by this move".
The British MEP added, "Janice Atkinson should do the honourable thing and resign, not prop up a group of Europe's most hateful and far-right parties".
The ENF has MEPs from seven member states - the minimum amount required to form a group - so as the only UK deputy, if Atkinson were to leave, the new formation would collapse.
Greens/European Free Alliance (Greens/EFA) group member Alyn Smith agreed with Bearder, saying, "she should resign, pure and simple. She was elected on a list, and has no personal mandate to flounce to this new nasty group".
He told Atkinson in an email, "I urge you to resign your seat. Presumably this will give you more time to fight the corruption allegations against you".
His colleague Ian Hudghton conceded that it was "perhaps not surprising that the far-right have managed to cobble together a ragbag of racists and extremists. Last year's European election saw a rise in the right-wing vote in many parts of Europe".
"This new group will remain on the margins of parliament's work. It is however important that progressives across Europe remain united in efforts to combat the politics these people represent."
Confederal Group of the European United Left/Nordic Green Left (GUE/NGL) chair Gabi Zimmer pointed out that, "now there are three right-wing, nationalist and anti-immigrant groups to the right of the conservative EPP."
"That makes it even more important for us to take resolute actions against the backward looking, nationalist and anti-social policies of the extreme right. The democratic forces in parliament cannot overlook the threat that this new group can pose to minorities across Europe, despite its facelift".
But the German MEP also argued that the EU itself was partly to blame for the rise of the far-right throughout the member states, saying that it "destroys the trust of its citizens by ignoring their concerns and expectations and representing mainly the interests of banks and corporations".
"Only a democratic EU dedicated to growth, employment and fair living standards can counter the appeal of these racist parties masquerading as defenders of the rights of ordinary citizens".
Meanwhile, representatives for Janice Atkinson's former EFDD group simply said, "whatever she does is beyond our control".