Speaking yesterday to MPs, Lord Patten said that he would stop taking the Tory whip in the Lords and would resign his post as president of Richmond Park Conservative Association.
However, he confirmed that he would not give up 40 years as "an old-fashioned Tory", especially as the BBC "protocols are clear that that isn't a requirement".
Lord Patten was giving evidence to the Culture, Media and Sport select committee in the first ever "pre-appointment hearing" for the chairman-designate of the BBC Trust.
The committee will give its view on his appointment, though the government will only withdraw his nomination if there is an all-party objection to him taking the role.
Earlier in the week, Labour called on Lord Patten to leave the Tory Party and give up some of his business interests before taking up the new post.
Asked by the committee whether he would be a "Conservative party stooge", Lord Patten replied: "Some people would say that, but I don't think that it would be true".
Tom Watson, a Labour MP and committee member, backed Lord Patten's decision to retain his Tory membership, yet questioned whether there would be a conflict of interest with his paid position on the international advisory board of oil giant BP.
Watson noted that the board had helped BP's management during last year's Gulf of Mexico oil spill, and so asked whether Lord Patten would be able to advise BP and chair the BBC should such a similar event occur.
In response, Lord Patten said that he only advises BP on "strategic and geopolitical issues", but if he thought there was a "question of a conflict" he would resign the post.
Lord Patten told the MPs that it was a "huge honour to help steer the BBC from an analogue to a digital age", despite admitting that he "hardly watched television".
He also talked tough on BBC pay, saying that "the ambition of BBC employees [is] to be paid almost the same as a bankers at Barclays".