OTTAWA - Prime Minister Justin Trudeau launches a cross-country tour today to touch base with grassroots Canadians.

But his tour, starting in eastern Ontario, takes flight under suspicions that it's all about helping the Liberal party add details about potential supporters and donors to its massive data base.

Liberal MPs in several cities Trudeau plans to visit have posted online invitations for those wanting to attend townhalls with the prime minister and they must provide their names, email addresses, postal codes and phone numbers in "mandatory" fields on the websites.

However, Trudeau spokesman Cameron Ahmad says no information collected on those sites is shared with the Liberal party of Canada. He says although registration is not required, MPs want contact information so updates can be sent in case of time or location changes.

But Conservative House leader Candice Bergen says she finds it "almost impossible to believe" contact data collected by Liberal MPs isn't used for partisan purposes.

The first leg of Trudeau's tour starts today in Ottawa and winds up in London, Ont., on Friday, with stops in such communities as Belleville, Kingston and Peterborough. The tour will also take the PM to Quebec, B.C. and the Prairies, then the Atlantic provinces and the North.