Theresa May is facing a Cabinet split over suggestions the Conservatives are poised to abandon a pledge not to raise major taxes after the election.
Philip Hammond, the Chancellor, suggested last week that David Cameron's pledge not to raise income tax, VAT or national insurance should be abandoned.
He said that the pledges “constrain the ability of the government to manage the economy flexibly”.
In a clear indication that the policy is still under discussion, Sir Patrick said Mr Hammond had been expressing his own views rather than that of the party.
Sir Patrick told the BBC’s Sunday Politics programme: “The simple fact is that what we have got to do is do the best things for the economy.
“We will be setting out in our manifesto in a few weeks time what the policies will be for the next Parliament.
“What Philip was saying was some of the areas he wants to address as Chancellor.
“What the Party will do is in its manifesto set out all the issues we are fighting on. It will set out very clearly the choice that we have in this country.”
He added: “What I'm saying is that in a few weeks time we will set the manifesto out, which will set the policies out which will be agreed by the Cabinet.”
It was suggested to Sir Patrick that Mr Hammond as Chancellor would be expected to decide upon the economic elements of the manifesto.
He replied: “We'll be talking about that in due course.”
Sir Patrick would not be drawn on whether the tax promises would be in the manifesto but simply said the “Conservative Party will want to see taxes reduced”.
The “tax lock” was a key manifesto pledge of Mr Cameron at the 2015 General Election.
But the party’s commitment to the lock was thrown into doubt on Friday after Mr Hammond appeared to criticise it as he stressed the importance of economic flexibility.
Mr Hammond, speaking in Washington, said: "I'm a Conservative, I didn't come into politics because I believed in higher taxes. I believe in lower taxes."
He went on: "But I also think we need to manage our economy sensibly and sustainably. It's self-evidently clear that the commitments that were made in 2015 manifesto did and do today constrain the ability of the government to manage the economy flexibly."
Mr Hammond had attempted to increase national insurance contributions for self-employed workers in his March Budget.
But he was forced to abandon the move after a fierce backlash by Tory MPs because it breached the “spirit” of the party’s manifesto commitment.
Damian Green, the Work and Pensions Secretary, distanced himself from the Chancellor’s comments on Sunday.
He was asked by ITV’s Robert Peston how he felt about fears that the Tories could be planning a tax raid on people on lower incomes.
He said: “Well, we’re absolutely not, we haven’t had a go at people on lower incomes, indeed we have specifically tried to and been successful in supporting them at a time when the public finances have had extreme difficulty so of course that’s what we, that’s what a Conservative government, a re-elected Conservative government would continue to want to do.”
Mrs May repeatedly declined on Saturday to rule out tax increases.
She insisted instead that the Tories will “always” be the party of low tax but her failure to explicitly rule out increases is likely to fuel concern among the party’s grassroots support.
The Prime Minister was pushed three times on Saturday to endorse the lock but she failed to do so.