The head of the European Union's executive body has criticised European members of parliament as "totally ridiculous", enraged by a high absentee rate during a speech by the prime minister of Malta, which has just completed a term running the bloc's presidency.

After EU Commission President Jean-Claude Juncker thanked the 30 of the 700-plus politicians in the huge atrium for showing up, he insisted that the "parliament is not serious" since legislators failed to attend Tuesday's keynote debate in larger numbers.

The session in Strasbourg, France, focused on Malta's six-month presidency of the European Union, which ended last weekend.

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EU Parliament President Antonio Tajani chided Juncker and asked for "a more respectful attitude".

"The Commission does not control the parliament. It is the parliament that should be controlling the Commission," Tajani said, to which Juncker retorted: "There are only a few members in the parliament to control the Commission. You are ridiculous."

Juncker added that parliament had to respect the presidencies of smaller countries - Malta has 415,000 people in contrast to the EU, which has half a billion.

'If Merkel or Macron were here'

The Commission prepares rules and regulations for the bloc and runs its day-to-day business. Juncker is considered a key leader of the 28-nation bloc. The parliament has increased its clout over the past year but many EU decisions are still made by the leaders of the member states or by the Commission, not by the European Parliament.

For many, being an EU legislator is still perceived as an easy job for politicians without a big national portfolio or veterans seeking a leisurely path to retirement.

The exchange at the legislature was even more remarkable since Juncker and Tajani belong to the same EPP Christian Democratic group.

EU Vice President Frans Timmermans said the two men discussed the incident and "then it was off the table again".

The views of the parliament bore out Juncker's assertion, with row after row of empty seats. Philippe Lamberts of the Greens groups, one of the few to show up, was seen applauding the rebuke of Juncker.

Maltese Prime Minister Joseph Muscat was attending the plenary. While he was still in the hall, Juncker referred to the German and French leaders while scolding the parliament.

"If Mr Muscat would have been Mrs Merkel - tough to imagine - or Mr Macron - easier to imagine - we would have had a full house. The parliament is totally ridiculous," Juncker said.

Muscat laughed during the incident and shrugged off the suggestion that small countries might matter less.

Timmermans said "this is what happens when impassioned politicians speak from the heart" before adding "especially when you are from a smaller country and you believe prime ministers deserve the same level of respect whatever the size of their country".

Gianni Pittella, the leader of the Socialist bloc, said attendance should have been better but added that "whenever we have major events, votes on major files, members of the European Parliament are there".

The presidency of the Council of the EU rotates among member states at six-month intervals. Estonia began its term at the weekend.