It specifically aims to revoke anti-gay laws within the Commonwealth, using business and political pressure.
Their arrest triggered international protests over the country's anti-gay laws.
Imagine passing an anti-gay law in San Francisco.
Malawi is among 37 African countries with anti-gay laws, and strong attitudes against homosexuality.
Tutu has said that in future anti-gay laws would be regarded as just as wrong as apartheid laws.
Blog: Thirty years ago, Harvey Milk led a successful campaign against a proposed anti-gay law in California.
More recently, a third possible reason for the anti-gay law has emerged from declassified Soviet documents and transcripts.
They also opposed a United Nations resolution that would have formally condemned discriminatory anti-gay laws.
In recent years Johnson has played down his previous support for the anti-gay law known as Section 28.