Labour MP Karl Chircop is in a critical condition after suffering a cerebral haemorrhage.
Dr Chircop, a family doctor - who will celebrate his 43rd birthday on Thursday - was rushed to Mater Dei Hospital after he collapsed on Sunday evening.
In a statement yesterday afternoon, the Labour Party said Dr Chircop was being treated at the Intensive Therapy Unit.
Labour leader Joseph Muscat and his predecessor Alfred Sant visited Dr Chircop in hospital yesterday, as did Social Policy Minister John Dalli and Acting Speaker Carmelo Abela.
Speaking at the start of the MLP's extraordinary general conference in the evening, Dr Muscat said the party was going through a "human drama" with one of its friends to be found in a very critical condition.
He said Dr Chircop was stable but critical.
"Let us all reunite in solidarity with Karl and hope to see him again," he said in a sombre voice.
Dr Chircop, a father of four, was appointed Labour's health spokesman by party leader Joseph Muscat only last month, a post that he is very happy in, according to Sta Luċija mayor Frederick Cutajar.
Dr Chircop was raised at Sta Luċija, only moving away a few years ago, Mr Cutajar said. Describing the young MP as a "very gentle and down to earth" person, the mayor said he is well loved by the people.
Labour MP Gavin Gulia, who is a good friend of Dr Chircop, expressed his shock in a comment on timesofmalta.com.
"We are all shocked. A great personal friend. God bless you," he wrote.
Tens of messages poured into the website, with people expressing their hope of a speedy recovery for Dr Chircop.
Labour MP Leo Brincat urged people to pray for the MP, whom he described as "a close colleague and a personal friend who was doing his utmost in his new role".
Resources and Rural Affairs Minister George Pullicino also posted comments on the website, saying his thoughts and prayers were "with Karl and his family", while deputy Prime Minister Tonio Borg described him as "a true gentleman".
Parliamentary Secretary Jason Azzopardi said he has "always known Karl to be so full of strength, health and charisma," describing him as "a true and rare gentleman".
Former MLP general secretary Jimmy Magro, PN treasurer Peter Darmanin, AD spokesman on sustainable development and local government Carmel Cacopardo and former Labour minister Joe Grima also wished Dr Chircop a speedy recovery.