Bob Geldof said leaders should think ahead of the G8 summit

The musician and anti-poverty campaigner made the comment during his speech at the Scottish Parliament's Conference on Africa event.

In a strongly worded address he called for a huge change in western attitudes towards the continent and its problems.

The Scottish Executive event looked at how Scotland could contribute to solving debt, trade and aid issues.

Geldof is one of 17 commissioners appointed to the Commission for Africa by Prime Minister Tony Blair.

We're a joke, we are a complete and utter disgrace and we perpetrate this falsity and this lie on the head of the already trodden upon, mute and weak Bob Geldof

He told more than 150 representatives at the conference in Edinburgh that the G8 leaders should not gather at Gleneagles in July unless they planned to change their attitudes towards African nations.

Geldof attacked the west's lack of progress towards the millennium development goals (MDGs) set in 2000 to eradicate extreme poverty and hunger; achieve universal primary education and halt the spread of Aids and HIV across Africa.

He said: "We are supposed to have arrived at the first stage of them this year. But we are so far behind achieving what we promised that the targets for 2005 will not be met until 2150.

"We're a joke, we are a complete and utter disgrace and we perpetrate this falsity and this lie on the head of the already trodden upon, mute and weak.

"In seven weeks, these seven men, plus one, who can resolve this, who can put this plan into immediate action now will meet in this country.

Jack McConnell invited Geldof to speak at the conference

"If they come here with the attitude that I know they currently have today, of doing nothing, don't come, stay at home, not welcome.

"On the other hand should you come with the intent to stop this open wound then you will be embraced and remembered throughout this century."

He added that doubling the amount of international aid to Africa would cost someone the equivalent of half a stick of chewing gum a day.

Geldof said: "We wouldn't blink, not a single person would receive less dole, less wages, would have to pay more tax,.

"It is the specific responsibility of Scotland, and their great task, to ensure that this is done.

"And it is the specific task of the first minister to not welcome them if they are not prepared to do it.

"And if you're not prepared to do it, don't come to Scotland, stay out."

I know that politicians respond to public opinion and public opinion needs to be heard more loudly and clearly in the next few weeks than it has ever been before Jack McConnell First Minister

The conference was also addressed by Jack McConnell, Salil Shetty, director of the UN MDGs campaign, and Kumi Naidoo, secretary general and chief executive of Civicus.

Earlier, Mr McConnell urged the public to support the Make Poverty History campaign, which is holding a mass rally in Edinburgh ahead of the G8 summit.

He said: "It is at times like this that the power of individuals, coming together to tell their leaders what they believe in, can make the politicians make the big decisions that will make the lasting difference.

"I know what Scottish public opinion is and I agree with it. I know the people of Scotland want to be heard.

"I am a politician. I know that politicians respond to public opinion and public opinion needs to be heard more loudly and clearly in the next few weeks than it has ever been before."

The conference came ahead of Mr McConnell's planned visit to Malawi at the end of May, where he will look at how the government can help development projects.