OTTAWA — Rob Nicholson, the longest-serving Conservative member of Parliament, isn’t running for re-election in the fall.

Nicholson, who was first elected in 1984 in Niagara Falls and held cabinet posts for more than a decade, says it’s time for him to focus on his family.

The 66-year-old has spent 24 years as an MP under three Conservative prime ministers, beginning in the government of Brian Mulroney.

Nicholson won his riding six times, first in 1984 and again in 1988, 2004, 2008, 2011 and 2015, with a stint in local politics in the 1990s.

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From 2006 until 2015, he was appointed by then prime minister Stephen Harper to several cabinet portfolios, including justice, defence and foreign affairs.

But Nicholson says one of his most memorable positions was that of parliamentary secretary to the justice minister earlier in his career, when he helped pass legislation making it illegal to possess child pornography.

“It was something that I believed was the right thing to do and it was in line with what was taking place in the world,” the married father of three told reporters Wednesday as he entered the weekly Conservative caucus meeting in Ottawa.

“I believe it was the last piece of legislation of the Mulroney government, but I never forget how proud I was.”

Nicholson was appointed in January to the National Security and Intelligence Committee of Parliamentarians, which serves as a high-level review body for the country’s security and intelligence agencies.

While he hasn’t said what he will do after departing federal politics, Nicholson said he will do what he can to ensure Conservative Leader Andrew Scheer is elected in October to govern the country.