Three previous prime ministers - Sir John Major, Tony Blair and Gordon Brown - are to join current PM David Cameron at the official memorial ceremony for Nelson Mandela in South Africa tomorrow.
Also attending the national memorial service in Johannesburg's FNB Stadium will be Deputy Prime Minister Nick Clegg and Leader of the Opposition Ed Miliband, said Downing Street.
It is thought to be the first time for many years that all of the UK's surviving prime ministers have travelled to an event abroad, and reflects the deep respect in which Mr Mandela is held within British politics.
The announcement came hours before MPs gathered at the House of Commons to pay tribute to the former South African president and African National Congress leader, who died last Thursday.
Large numbers of dignitaries from around the world are set to join tens of thousands of ordinary mourners tomorrow to hear heads of state including South African President Jacob Zuma deliver addresses in tribute to the country's first democratically-elected and first black president.
The Pretoria administration has said 53 serving heads of state and government have already confirmed that they will be among a gathering expected to number 80,000. Among those expected to be there are US President Barack Obama and United Nations secretary -general Ban Ki-moon.
Sir Richard Branson and singer Peter Gabriel - who devised "The Elders" forum of statesmen and activists set up by Mr Mandela - are also due to attend.
The FNB stadium, in the Johannesburg township of Soweto, was the venue of the anti-apartheid hero's final public appearance at the closing ceremony of the 2010 football World Cup.
Mr Mandela's body will then lie in state at South Africa's seat of government, the Union Buildings in Pretoria, until he is laid to rest in a s tate funeral at his hometown of Qunu in the Eastern Cape.
The Prince of Wales will be among a smaller number of dignitaries travelling to the remote rural location for that service.
Departmental question time has been suspended in the Commons today to allow MPs to honour the memory of the former South African president.
Speaker John Bercow will make the opening address, followed by words from Mr Cameron and other party leaders.
With many MPs expected to want to commemorate Mr Mandela, the rest of the day's House business may also be scrapped.