Lord Rothermere has given details of dozens of meetings with senior politicians, including David Cameron and Culture Secretary Jeremy Hunt.
The chairman of the Daily Mail and General Trust, which owns the Daily Mail and Mail on Sunday, described a visit to Chequers in July 2010 with the Prime Minister and his wife Samantha.
The cross-bench peer and Lady Rothermere also spent a weekend with George Osborne and his wife in November 2009, as well as socialising with Liberal Democrat leader Nick Clegg, Gordon Brown and Tony Blair.
But giving evidence to the Leveson Inquiry, Lord Rothermere insisted there had been nothing improper about the contacts.
And he stressed that, despite people's worries about the influence and behaviour of the press, the Daily Mail had "acted ethically".
"I can see why people have concern for the press. After all it does appear to have quite a lot of power and certain elements of our industry have not necessarily acted in the right way, apparently," Lord Rothermere said.
"I feel pretty confident that our newspaper has acted ethically and I am willing to stand up for us."
He accepted that the Mail had to be more protective of its reputation in the wake of the furore about media standards.
"As a leading newspaper we have to take that on board," the peer said. "However, ultimately the commercial reputation we have is with our readers and advertisers.
"They continue to read our newspapers and advertise with our newspapers."