Brussels - Thousands of members of the Congolese diaspora gathered in Brussels on Sunday to pay their last respects to their nation's opposition leader Etienne Tshisekedi, who died in the Belgian capital last week.After a three-day funeral wake, Tshisekedi's coffin was put on display for several hours in a large hall made available by city authorities, near the famous Atomium tourist attraction, AFP journalists said. They came from across Belgium but also travelled from France, Britain and Germany, to pay a final tribute to "Tshishi", as his supporters called him."He is dead but his spirit remains among us. We will keep his heritage alive," one man told the crowd through a microphone, drawing applause in a hall filled with a festive atmosphere and many tearful eyes.Tshisekedi died on Wednesday, having left the Democratic Republic of Congo eight days earlier for medical care abroad.His death has plunged the vast African country further into uncertainty. He played a key role in negotiations aimed at peacefully resolving the political crisis triggered by President Joseph Kabila's refusal to leave power.Kabila's mandate ended on December 20 but he has vowed to remain in office until elections can be held to choose a successor.Tshisekedi became a dissident in 1979-1980 when he denounced the arbitrary rule of dictator Mobutu Sese Seko, whom he had supported in gaining power after the country's independence from Belgium in 1960.He then led opposition to Laurent Kabila, who took office by force in 1997, followed by his son Joseph who became president after his father's assassination in 2001.Beaten in 2011 elections tainted by massive irregularities, Tshisekedi refused to recognise Kabila's legitimacy to the very last.