Ed Miliband will put green politics at the heart of his political agenda in an impassioned speech Tuesday to Labour Party activists.
Speaking at the party's last conference before the general election, the Labour leader said he felt seeing green technology and low-carbon industries thrive as part of a 10 year plan to shape "Britain 2025" was one of the "most important" things he could do in politics.
"It is incredibly important to our economy today," he is set to say. "And it is the most important thing I can do in politics for the future of my kids and their generation."
Miliband, who served as energy and climate change secretary in the last Labour government, will promise to create one million new jobs in green tech industries. He will also attack the coalition for failing to "do its bit" to back green industry. The criticism will be especially acute as David Cameron promised before becoming prime minister to lead the "greenest government ever".
"Under this government, Britain lags behind Germany, Japan, the United States and even India and China for low-carbon green technologies and services," he will say. "So many of our brilliant businesses are desperate to play their part in creating their jobs of the future but they just can't do it unless government does its bit. With our plan, we will."
Miliband's green priority will be just one part of his six-point plan, which he will tell activists is his programme to "build that better future for you and your family, wherever you live in the United Kingdom".
The Labour leader will commit to boost apprenticeships, ensuring as many school-leavers use them as attend university, to offer "good jobs" at decent wages and to protect the National Health Service.
He will also tell activists that Labour is "the party of hard work fairly paid" while the Tories are the party "of wealth and privilege".
Meanwhile Shadow chancellor Ed Balls has refused to comment on how the proceeds of a mansion tax will be spent - despite speculation the funds will be ploughed into the NHS.
Mr Balls repeatedly refused to answer the question at a Huffington Post UK fringe event at the Manchester conference .
He said: "We announced a number of things today... there has been lots of speculation.
"The things I wanted to announce in my speech today, I have announced. The things I have not announced in my speech today will be in a different speech.
"What I actually said in the speech is these are decisions we will make to reduce the deficit in a fair way and safeguard our vital public services. I think most people in the real world agree with both of those objectives."
Pressed on the NHS specifically, Mr Balls said: "When I was asked whether Frank Field's proposal for another National Insurance rise to be Labour's policy, I said it wasn't Labour's policy, and I said working people were already paying a lot of tax.
"I think at the moment working people feel they are paying rather a lot of tax and therefore I'm not proposing even more taxes... however, we will do whatever it takes to make sure the NHS is safe.
"We will do what it takes."
Mr Balls fell silent when pressed whether "whatever it takes" meant using a mansion tax, before adding: "I'm not trying to dodge the question, I'm just saying to you I'm not answering the question."
Former Labour spin doctor Damian McBride sparked the speculation today when he said of the mansion tax: "Last time I looked, the current priority was the reintroduction of the 10p income tax band.
"But today we learn that the 10p policy will instead be paid for by abolishing Cameron's cherished marriage tax break, neatly demolished by Balls in his speech.
"So how is the mansion tax money now going to be spent?"