Gordon says government lobbying by former ministers risks being "a stain on our democracy".
The US and Europe should each pay a quarter of the cost to help vaccinate poorer nations, says the former UK PM.
In the final part of Andrew Marr's national saga, Britain enters the post-Thatcher era. Many have done well during the Thatcher years, but now boom is turning to bust.
By Jennifer Scott
BBC News online political reporter
By Nick Eardley
BBC political correspondent
The former British prime minister on how Joe Biden will change the US presidency.
Former Prime Minister Gordon Brown has called on Boris Johnson to extend free school meals.
By Kate Whannel
Former prime minister Gordon Brown has called the government's planned Internal Market Bill "self-harm".
The UK and Scottish governments must radically increase their coronavirus testing targets, former prime minister Gordon Brown has said.
A report from Our Scottish Future, a think tank launched by the former Labour leader, says testing needs to be stepped up dramatically.
Mr Brown said the Scottish government's target for a 15,500 daily testing capacity by the end of May is not enough as routine checks on 800,000 key workers north of the border are needed.
He added: "It's now clear that mass testing across the community is the only way to give people the confidence to get back to work."
The G20 must persuade President Trump to back the WHO, the ex-UK prime minister Gordon Brown says.
The former UK prime minster says the world needs to overcome "aggressive nationalism" and act globally.