The Conservatives' lead over Labour as they begin their party conference has fallen to 1% from 4% in mid-September, according to a Sunday Mirror/ICM poll.
Mr Maude says there will be much substance from the conference
The poll of 1,029 people on September 28-30 put the Tories on 36%, Labour on 35% and the Liberal Democrats on 19%.
Earlier, a survey by YouGov for the Daily Telegraph put Labour and the Tories level on 36% - compared with a Tory lead of 7% earlier in the month.
YouGov questioned 1,847 adults online between September 27 and 29.
The YouGov poll also found 54% of those questioned thought it was "hard to know what the Conservative Party stands for at the moment."
The fall in the Conservatives' ratings comes as the party gathers for its annual conference in Bournemouth.
Tory chairman Francis Maude told the BBC that the public would see "a great deal of substance" from the conference.
"They'll see people involved in the policy groups setting out some of the thinking, the emerging thinking, the analysis there is of the problems Britain faces today and is going to face tomorrow and the way in which we're addressing those problems," he said.
"So you're not going to end up with a manifesto at the end of it and you're going to end up with a very strong sense of the direction that the party is going in."
Mr Maude also said the party would be "less arrogant about the ability of politicians to have all the answers" - he insisted that the leadership wanted to engage more with the public and give them more responsibility.
He said David Cameron's "new direction" would show that the party is becoming "more green, more local, looking at devolving power".