It's no secret that Tom McMillan is critical of the modern Tories.

The former federal cabinet minister and Progressive Conservative member of Parliament for Hillsborough, P.E.I., just published a book about it.

Not my Party: The Rise and Fall of Canadian Tories, from Robert Stanfield to Stephen Harper, is as much part-memoir, as a history of the last 50 years of the Tories in Canada.

"The book is very much about the Conservative Party of Canada," McMillan said.

"Not from the point of view of a partisan but from that of someone who is deeply concerned about what has come of the grand old Tory party which no longer exists, at least for the time being."

A party that lost its roots

McMillan said it took him about five or six years to write the book but a lifetime of experience to inspire it.

While Not my Party recounts his own experience in politics — from his early years as policy secretary for Robert Stanfield, to being a minister in Brian Mulroney's cabinet — it also laments the end of the Progressive Conservative Party when it merged with the Canadian Alliance Party in 2003.

The takeover, as McMillan calls it, created a new Conservative Party that lost many of its historic roots.

"And that's exactly what happened," he said.

"These very cunning right-wingers saw an opportunity to take over an established institution with a broad membership and a history and heritage, and recast it in a completely different mould."

McMillan said he consulted a wide circle of people while writing his book, from academics to policy specialists and former colleagues.

But he also talked to people who never voted for the Tory party, who shared his thoughts on the Conservatives today.

"I heard a lot from these people, they informed my book, I consulted them, many of them guided it," he said.

"And in that sense my book is not only the voice of Tom McMillan, author. It's the voice of many people who share my views on the subject."

Return to old principles

Not my Party: The Rise and Fall of Canadian Tories, from Robert Standfield to Stephen Harper, is as much part-memoir, as a history of the Conservative Party in Canada. (Indigo Books) With the defeat of the Tories in the 2015 election, he said Not my Party took on a new urgency.

The Tories will now have to reshape their party, starting with the decisions made by their new leader, he said.

McMillan hopes his book will offer some insight on how the party can return to old principles and reclaim its place in Canadian politics.

"I'm not presenting myself as some professional critic of the Conservative Party," he said.

"But what I do is express a wish in the book that other people of like mind … who are progressive and reformist and believe in that kind of party, will link their voices with mine and put pressure on the Conservative Party frankly to come to its senses, to restore its soul."