European Union leaders have raised concerns over the lifestyle of Jean-Claude Juncker, claims British conservative paper The Daily Telegraph, ahead of the 27 June summit in which Prime Minister David Cameron is expected to force an unprecendented vote on the Luxembourgish politician’s candidacy for the European Commission presidency.

The daily writes that separate diplomatic sources in Brussels, one of whom claims Juncker “has cognac for breakfast,” have confirmed that Juncker’s “alcohol consumption has been raised by a number of leaders since the parliament election”.

The paper observes, however, than some claims have been denounced as rumour —

Sources also described how Mr Juncker “chain-smoked” through a series of meetings on Thursday and disclosed that he is attempting to get rules changed so that he can smoke in buildings in Brussels. A source close to Mr Juncker who has been present at EU summits, said: “This is quite ridiculous and 100 per cent untrue. There was absolutely no discussion of this.”