The founders of Live Aid have urged a million people to descend on Edinburgh to campaign against world poverty as G8 leaders meet at Gleneagles.
Bob Geldof and Midge Ure want people to attend an anti-poverty rally in Edinburgh on 6 July.
"What's better - two days of work? Two days of geometry? Or participating in something you will remember all your life," Geldof asked.
Police have warned that public safety
must remain their first priority.
The former Boomtown Rats frontman said he was confident Edinburgh could deal with up to a million people travelling to the city.
Geldof and Ure announced a series of concerts around the world on 2 July, after which they want people to head for Edinburgh in time for an anti-poverty "party" four days later in what they are calling "The Long Walk to Justice".
Lothian and Borders Police were already preparing for a Making Poverty History march on 2 July and are now concerned about problems caused by such a massive subsequent influx of people.
Speaking about the nature of the Edinburgh event, Geldof told the BBC: "It's going be a party. I like parties, I'm quite good at organising them and this is going to be the biggest party ever held.
"If the principals who are in the middle of this party - the eight leaders who can control the world's economic destiny - don't want to come to the party, then don't show up in our country, you're not welcome to the party.
"If they don't want to change the world just that little bit - so that a continent eight miles from Europe, the poor people of that continent don't have to die, live on our television screens every night for ever - if they don't want to stop that, if they don't want to do what they've always promised, don't come."
'Ban the Bomb' comparison
Geldof's Band Aid partner Midge Ure is co-ordinating the protest. He said plans were being made for a convoy of planes, cars, trucks, ferries and private boats to take people to Scotland.
"We don't care how you get there. But you have got to get to Edinburgh and let them know what we think," he declared.
"Give up home and school for a week. It will be just like the Ban the Bomb protests in the sixties - something special.
"You may never have this opportunity again. These people are on our shores and we can do something. Stand up and be counted."
Elaine C. Smith and Ken Stott are supporting the anti-poverty drive
Every householder and religious institution in Edinburgh was urged to offer hospitality to the protesters.
"We want every church, chapel, synagogue and mosque to open their doors and let them in," he went on.
"Scotland has an amazing history of being hugely big-hearted."
The people of Scotland should have a right to influence the G8 summit, according to the musician.
"Scotland is a little miffed that this is happening on their own doorstep and they are not invited."
Lothian and Borders assistant chief constable Ian Dickinson said the force understood the motivation of those who wanted to eradicate poverty in Africa and officers would help them to achieve their aims.
"Public safety is my over-riding concern and that requires consultation and planning," he pointed out.
"We need to know the realistic scale of events and work with organisers to achieve what is possible.
"We were already planning for more than 100,000 people to take part in the Make Poverty History march which would have been the biggest event ever in Scotland.
"Now there has been talk of up to a million people coming to Edinburgh but frankly it is difficult to conceive how they could all get to this area in the first place and where they could assemble in safety.
"No-one wants tragedy to distract world attention from the real aims of the campaigners."
Mr Dickinson said the force could not allow the policing capability or any infrastructure to be overwhelmed and compromise the safety of those involved.
The SRU was worried about the turf being ripped up
As well as the rally on 6 July, a free concert is being organised for Murrayfield.
There were concerns that the turf could be ruined and the Scottish Rugby Union said it could not afford to replace it but the charitable foundation of Scots tycoon Tom Hunter has assured them they will not be left out of pocket.
Organisers are said to be approaching acts such as Travis, Franz Ferdinand, U2, Oasis, Paul McCartney, Robbie Williams and Eric Clapton.
Geldof also announced five free concerts, under the banner title Live 8, will take place on 2 July in London, Paris, Berlin, Rome and Philadelphia.
Among the acts performing will be Elton John, Paul McCartney, U2, REM and Madonna.