This would also require all the major parties to have their tax and their future spending plans audited by the independent Office for Budget Responsibility before a general election.
Mr Timms, who worked on the manifesto's social security policy, has admitted that he didn't know about plans to introduce a budget lock until it was launched on Monday.
"It is a very interesting approach, it's an unusual approach, it's different from what's happened in manifestos in the past, and I think it's a very good approach actually because its starting with the assurance for everybody that nothing that's in this manifesto requires extra borrowing, said Mr Timms speaking on Premier's News Hour.
"Where there's extra spending that we're committing to, we're explaining where that spending is coming from. I think it'll succeed in building reassurance about the responsibility that the next government, if it's a Labour government will exercise."
In a speech in Manchester, Ed Miliband's also promised to, increase the minimum wage, and create more NHS jobs.
With 24 days to go until the General Election, Mr Miliband said: "The reason we can make these commitments is because we will make sure those with the broadest shoulders bear the greatest burden.
"So we'll reverse David Cameron's tax cut for millionaires to help pay down the deficit.
"We'll crack down on hedge funds who avoid paying their fair share. We'll stop HMRC operating double standards.
"And we'll do something that no government has done for over 200 years - we'll say enough is enough to the people who live here, work here, send their kids to school here but don't want to pay taxes here and we will abolish the non-dom rule."
The Conservatives say Labour's deficit plan is 'an impossible leap of faith', while Nick Clegg has said the manifesto's 'not worth the paper it's written on'.
Stephen Timms speaking to Premier's Des Busteed on the News Hour:
