Jean-Claude Juncker was once again seen struggling to navigate a small set of stairs at a key international summit today.

The European Commission President, who last week told the Prime Minister the EU would offer no further concessions on her Brexit deal, was photographed seemingly losing his balance and having to be held and helped by a pair of aides.

It is the latest of several high-profile events, including a NATO summit, at which the politician has looked unsteady on his feet.

Today the 64-year-old was attending the High-Level Forum Africa-Europe summit, at the Spanish horse riding school in the Hofburg palace in Vienna, Austria.

The summit of European and African leaders focused on the crucial matters of economic development and migration, which have come to be among the EU's defining challenges in the wake of mass migration from North Africa and the Middle East triggered by the Syrian civil war.

European Commission President Jean-Claude Juncker (in grey shirt and grey tie) stumbles as he arrives at the welcome dinner of the High-Level Forum Africa-Europe at the Spanish Horse Riding School of the Hofburg Palace in Vienna, Austria, today

A female aid with an 'EC' branded bag is seen seemingly leaning her body weight against Mr Juncker to steady him, as a man supports his upper body from behind

The Commission President, who earns more than 300,000 Euros a year plus significant allowances and undisclosed expenses, seems to right himself in the next photograph

The woman to his left continues valiantly to check her phone while helping Mr Juncker as he seems to stumble again on his way to dinner

Later at the event Mr Juncker, whose previous job was as Prime Minister of Luxembourg (pop: 590,000), seemed in high spirits, high-fiving, kissing and hugging fellow world leaders.

He shared an enthusiastic high-five with Croatia 's Prime Minister Andrej Plenkovic and then shared a hug and a clinch with Estonia's Prime Minister Juri Ratas - all without leaving his seat at the dinner.

It is not the first time the well-remunerated politician's health and habits have been called into question.

President of the European Commission Jean-Claude Juncker (right) shares a high five with Croatia 's Prime Minister Andrej Plenkovic at a dinner organized by the High-Level Forum Africa-Europe at the Spanish horse riding school in the Hofburg palace in Vienna

Mr Juncker closed his eyes as he shared this seated hug with Estonia's Prime Minister Juri Ratas

Wrapping his left arm around the Prime Minister's neck and continuing to shake his right hand, Mr Juncker continues to speak closely with Estonia's Prime Minister Juri Ratas

This July the European Commission President was attending a dinner at the NATO summit in Brussels attended by US President Donald Trump and a number of other world leaders.

Mr Juncker was seen stumbling and swaying to the extent that the presidents of Finland and Ukraine, among others, had to help keep the 63-year-old upright.

Dutch Prime Minister Mark Rutte also stepped in to guide Juncker.

Footage from the summit also shows him struggling to make it up some steps and being held by the arm, at times by two other people.

Juncker took a remarkably long time to descend from a podium after a photoshoot with the other world leaders in July

In May of last year he was reportedly 'drunk and bumping into furniture' at a UN Peace Summit during critical talks.

Mr Juncker was said to be 'very visibly p**ed' during talks over Cyprus, which has been split between Greece and Turkey for decades, in Geneva in May 2017.

A diplomat also said that the 62-year-old's familiar behaviour with some young aides was 'embarrassing'.

A source told The Sun: 'He was bumping around into things, and going up to junior members of staff for conversations. It was odd behaviour, and a little bit embarrassing for everyone'.

And this July he was branded an alcoholic who binges on gin and leaving his deputy to govern, in an explosive new account by Brussels insider Jean Quatremer - a French journalist who has covered the EU for years - in The Spectator.

He said he had heard from sources across Europe that the EU politician is 'a little too fond of the bottle' adding that one former minister told him: 'When a bailiff brings him a glass of water at a council of ministers, we all know it's gin.'

Mr Juncker has repeatedly denied claims that he is an alcoholic and insisted that his sometimes shambolic appearance is down to chronic back pain known as sciatica.

He hit back at reports of his drinking in Mr Quatremer's story and denied the allegations when speaking to reporters.

Asked directly if alcohol played a role in his stumbling at NATO, he said: 'I'm really impressed by the interest some people are taking in these not even marginal issues and I am asking for respect.'

He added: 'I had sciatica and moreover I had cramps in my legs' adding that he 'laughed at the pettiness' of what was being said about him.