In an interview with German media, the outgoing President of the European Parliament Martin Schulz said Brussels was "treading water" because leaders of individual EU countries are failing to promote a pro-EU vision at home.
Schulz, who has been an influential figure in European politics for more than a decade, partly blamed national leaders for lacking the political courage to promote and implement EU policies in their home countries.
In an interview published on Thursday by German daily Süddeutsche Zeitung, he said that this lack of courage has in turn enabled anti-EU sentiment and nationalist far-right parties to grow across the continent.
Agreements not respected
Guntram Wolff, director of Bruegel thinktank, which focuses on the European economy and its governance, agrees with Schulz on this point.
"I would certainly concur with [Schulz's] analysis in the sense that European leaders agree often here on issues in Brussels, then go home and don’t implement what is decided here," he comments. "This is a fundamental problem because we cannot create a union in which agreements are not being respected."
However, Wolff also stressed that the EU has to have a clearer vision of its own responsibilities vis-à-vis its 28 member states.
"There is a deeper structural problem in the sense that, for some issues, it is just asking too much from the member states to deliver on things that ultimately need to be European responsibilities."
According to Wolff, the EU's responsibilities should include border control, which ties into the ongoing migration and terrorism problems currently facing the continent, as well as preventing tax evasion and fraudulent business and finance practices. He says that these issues are often too large to be taken on by individual countries.
UK also in shambles
Schulz's warning comes a day after the resignation of the UK ambassador to the EU, Ivan Rogers, who was responsible for negotiating Brexit terms in Brussels.
In his resignation letter, Rogers criticised Downing Street for its lack of a clear exit strategy.
But former member of European Parliament Brendan Donnelly, who now heads the British thinktank Federal Trust, says he "understands the frustration of Sir Ivan" but points out that his predecessor's claim is not entirely true.
"I think the remark that there’s no negotiating strategy is slightly unfair," he told RFI. "There is one, it’s just an entirely unrealistic and uncredible one."
Donnelly explains: "The negotiating strategy is that if Britain insists long enough that it wants to have a better balance of rights and responsibilities in its relation with the EU, eventually our partners will see the justice of that cause."
Rogers replaced by Barrow
Downing Street moved quickly to appoint a replacement ambassador to the EU.
Sir Tim Barrow, a former ambassador to Russia, has already served at Britain’s EU embassy in Brussels and has been described as a "tough negotiator".
But Bruegel's Wolff warns that Barrow still has a difficult road ahead.
"He has to be the communication link between the European institution and London-based administration, as every ambassador to the EU is. It's a fairly clear job description but it’s going to be a fairly difficult task to implement because negotiations are going to be cumbersome, acrimonious, and antagonistic."
The main task at the moment is transmitting the right information to London, he adds. "Once the official negotiations start he has to implement what London asks him to implement."
Certain British politicians have said they are happy to have a seasoned career diplomat as their new EU ambassador.
"It's the toughest negotiation in our lifetimes and I think he is up to it," former British ambassador to Lebanon Tom Fletcher told BBC radio. "I have seen him in Brussels. He knows the corridors, he knows the characters."
But anti-EU politicians have bemoaned the appointment of another Brussels insider. Ukip MP Gerard Batten said he was disappointed by the appointment, as Barrow represents “another career diplomat wearing a Brussels jersey”.