The Labour MP and former chancellor reacted after speculation that senior politicians were being drafted in to take a more prominent role.
Mr Darling, in Edinburgh to launch the latest Better Together advertising campaign, said the movement has "many voices".
"I will be doing an awful lot in this campaign and you'll see others, MSPs, people who're not anything to do with politics at all," he said.
"It's important that everybody gets engaged in this, but I intend to lead this campaign through to the finish.
"I've strengthened the team because I think it's the important thing to do as we reach the final stages, and we'll continue to do everything we possibly can to get the biggest vote we possibly can come the 18th of September."
He referred to recent interventions by former prime minister Gordon Brown, ex-home secretary John Reid and shadow foreign secretary Douglas Alexander.
More voices will emerge after the European election campaign finishes later this month, he said.
He conceded he does not know where the rumours about his leadership are coming from.
"If you go and ask people what they're bothered about at the moment, what they're bothered about is the issues in this campaign," he said.
"Frankly, who's doing what is of minor significance compared with the huge issues like what currency will we have."
All senior politicians have to put up with their leadership being questioned, he said.
First Minister Alex Salmond is also challenged over his direction, including from within the SNP, Mr Darling said.
The single biggest issue is the question of independence and what the country might look like after the vote, he said.
Mr Darling claimed the SNP is already putting people off by "shutting down" debate and criticism.
He highlighted concerns from opposition members of Holyrood's Public Audit Committee who accused the SNP of using its majority to remove criticism of Scottish Government policy on police reform.
"If this is how the Nationalists behave today, how will they behave if they had complete control over everything?" he asked.
"Where there is no means of exploring these things because they just shut everything down. It's bad for democracy. Any political party in government should not be afraid of the fact that from time to time there will be criticism and legitimate questions."
He continued: "Whether it's me, whether it's Standard Life, whether it's the banks, whether it's Barrhead Travel - anyone who says 'Excuse me, I don't believe you, I've got a question' gets shouted down and subject to unacceptable abuse."
Meanwhile, A formal currency union between an independent Scotland and the rest of the UK will not happen, George Osborne has told MPs.
The Chancellor said it was a "no ifs, no buts" position as he insisted there would not be a deal to allow Scotland to share sterling after independence.
The three main Westminster parties have all ruled out a currency union, but doubts about the Government's position surfaced earlier this year when an unnamed minister was reported as saying "of course" there would be a deal done to share the pound.
But Mr Osborne said: "The currency is one of the most important issues in the independence debate. All the evidence suggests that people in Scotland value highly the stability and security of the UK pound, backed by the strength of the Bank of England and taxpayers from across the whole of the UK."
He said he wanted Scotland to keep the pound "but the only way this will happen is if we stay together".
"The nationalists' preferred plan is to replace our UK pound with something very different to what we have now, an unstable eurozone-style currency union which wouldn't work at all for Scotland or the UK," he said.
"It's a plan where Scotland leaves the UK but the Scottish nationalists still expect taxpayers in the rest of the UK to continue to provide a safety net.
"It's a plan where the nationalists want to be independent but make Scotland's economic policy dependent on another country in which it no longer has any say or representation.
"That's why it's a plan that simply doesn't make sense."
Mr Osborne told the Commons Scottish Affairs Select Committee: "As Chancellor of the Exchequer it is my obligation to explain that no currency arrangement under independence will be the same as the strength and stability of one UK, with one UK pound.
"The people of Scotland deserve straight answers to straight questions and you have had straight answers from the Labour shadow chancellor, the Liberal Democrat Chief Secretary and from me the Conservative Chancellor.
"We have all made it clear that there will be no currency union if Scotland becomes independent, no ifs, no buts. An independent Scotland would not share the pound with the rest of the UK."
The committee's Labour chairman Ian Davidson said Mr Osborne's announcement that Scotland would not be able to share the pound, made on a visit to Edinburgh, was a "presentational disaster".
He said: "It looked as if it was some English Tory coming up to tell us what we could and couldn't do."
Mr Osborne said he had an obligation to provide the people of Scotland with the facts about the consequences of independence.
He told the MPs that the legal position was clear that the rest of the UK would retain the central bank - the Bank of England - which stands behind the pound.
"It is not like a divorce where you are dividing up the CD collection, this is something very different," he said. "This is a fundamental set of arrangements intrinsic to the UK and it's not just a physical asset that would be shared."
Treasury permanent secretary Sir Nicholas Macpherson denied that the Chancellor had pushed him to warn publicly against a currency union.
He also dismissed as "wrong" suggestions that he had abused his position by making his view known.
"If I thought it was the wrong thing to do, to publish it, I simply would not have done it," Sir Nicholas said.
"This was very much my idea and I think it was the right thing to do."
Sir Nicholas said there were "exceptional circumstances", because the Treasury had responsibility for the currency.
He also had a duty as the department's accounting officer to ensure the Government paid the lowest possible interest rates on debt.
A "lack of clarity" about what the Treasury thought could have pushed those costs up, he argued.