The group opposing Question 2 on the ballot Tuesday announced Saturday that former Boston Mayor Ray Flynn has come out against the ballot measure.

The Coalition for Safe Streets said the Massachusetts Catholic Conference mailed a letter Flynn wrote denouncing the ballot measure to 2,200 statewide parish communities.

Question 2 would decriminalize possession of small amounts of marijuana.

In the letter, Flynn wrote that marijuana is a gateway drug. Question 2's success, Flynn also wrote, would weaken the state's drug laws and send the wrong message to children.

"This is a quality of life issue," Flynn wrote, "If approved, this proposal would have a negative impact on the stability of the family and society.  As a society, we need to send the correct message to young people that drugs are NOT the answer."

Flynn joins many prominent Bay State pols who have endorsed the effort to defeat Question 2 including Gov. Deval Patrick (D-Milton), Boston Mayor Tom Menino (D), Attorney General Martha Coakley (D-Medford), U.S. Sen. John Kerry (D-Boston) and many of the state's district attorneys.

However, recent polling shows the group behind the measure, the Committee for Sensible Marijuana Policy, holding an advantage over the question's opponents, 51 percent to 31 percent.