Harriet Harman, the Minister for Constitutional Affairs, has promised more public involvement in big foreign policy decisions such as the decision to go to war in Iraq if she achieves her ambition to become the UK's first female Deputy Prime Minister.
Poverty in Africa, war in the Middle East and other big issues around the globe have become too important to be left to the Prime Minister and his circle of foreign policymakers, she said.
Her words, on the eve of the Labour Party conference in Manchester, will be seen as an indication of how problems such as Britain's standing in the world will be handled if Gordon Brown takes over as Prime Minister. Mr Brown and Ms Harman are allies, although he has not given any public support to her campaign for the deputy leadership.
The Treasury minister Ed Balls, one of the Chancellor's inner circle of advisers, has told the BBC that when Mr Brown goes to Europe to negotiate with other EU heads of government, he will be like Margaret Thatcher. "There was a phase on the European budget where she [Thatcher] stood up for Britain's interests and got a much better, fairer outcome," Mr Balls told the BBC's political editor, Nick Robinson, in an interview to be broadcast on Radio 4 this evening. "Going to an international meeting, the easiest thing to do is draft a fudge communiqué and go home, but if you want to make change, that's not good enough, and it's the people who are banging the table and saying, 'it's not good enough, we've actually got to do something', they're the change-makers."
Ms Harman, who backed military action in Iraq, has said that while the UK should remain an ally of the United States, the new Prime Minister would need to be blunt in criticising actions with which the Government disagrees, such as detention without trial in the camp at Guantanamo.
She also said that the Government needed to be more open in foreign policy-making.
"People want to have a say. They've shown that as they've marched in their millions on Africa. They are concerned about how foreign policy interacts with things that are very close to home like immigration, like security," Ms Harman said in an interview with the GMTV Sunday programme, to be broadcast tomorrow.
Ms Harman has announced that she will run for Labour's deputy leadership because she believes it will be essential that Gordon Brown should be elected on a "balanced" ticket.
But she told yesterday's London Evening Standard that she was not seeking a public endorsement from Mr Brown. "Frankly, even if he said that he did not want me to run, I would do so because I am pretty certain I am the best person to do it."