European lawmakers on Thursday formally demanded the "immediate release" of captive Israeli soldier Gilad Shalit, seized by Hamas fighters almost four years ago.

"This young man lives in a cave, with no visiting rights, no doctor, no lawyer, no mail, no trial (and) no Geneva Convention (of human rights)," said Belgian liberal MEP Frederique Ries.

He was speaking during a debate in the European parliament's Strasbourg chamber, watched by Shalit's father, Noam.

The parliamentary resolution also "urges Hamas to allow the International Committee of the Red Cross to visit Sergeant Shalit without delay, and to permit him to communicate with his family."

EU foreign affairs chief Catherine Ashton, who is due to visit Israel later this month, and who has been given permission to enter Gaza, met Shalit senior briefly on Wednesday.

Israel is reportedly prepared to release around 450 Palestinian prisoners in exchange for Shalit, who also holds French citizenship, and who was captured in a deadly cross-border raid from Gaza by Hamas fighters in June 2006.

Prime Minister Benjamin Netanyahu said on Tuesday that Israel was still waiting for a response from Hamas, three months after lodging its latest offer.