More than two dozen current and former law enforcement officials in the United States – including police officers, prosecutors and judges -- are warning the Canadian government against mandatory minimum sentences for minor marijuana offences.

In a letter addressed to "The Senate of Canada" and copied to both the prime minister and provincial premiers, a group calling itself Law Enforcement Against Prohibition (LEAP) advocates for the "taxation and regulation of marijuana in Canada."

The group, which says it aims "to end the substantial harms of marijuana prohibition in the United States," says anti-marijuana laws have devastating social consequences, from an increase in organized crime activity and gang violence, to corruption and social decay.

"We are also extremely concerned that Canada is implementing mandatory minimum sentencing legislation for minor marijuana-related offences similar to those that have been such costly failures in the United States," the letter says.

"These policies have bankrupted state budgets as limited tax dollars pay to imprison non-violent drug offenders at record rates instead of programs that can actually improve community safety. Marijuana prohibition drives corruption and violence and tougher laws only worsen the problem."

The letter appears to be a response to Bill C-10, known as the Safe Streets and Communities Act, which includes mandatory-minimum sentences for drug offences. The bill is certainly being studied by the Senate.

LEAP spokesperson Eric Sterling likened mandatory punishments for minor drug infractions to U.S. alcohol prohibition laws in the 1920s and early 1930s.

The prohibition only led to more crime and violence in the country, ultimately failing in its intent to protect the public, Sterling told CTV News Channel on Wednesday.

"None of the protections that exist in all businesses that are lawful exist in these criminal matters, so you end with the most violent people being able to dominate these organizations," he said.

"Then, a guy who's driving the car gets treated like the head of the organized crime syndicate who you're trying to target."

Sterling said there's "a great deal of room" within the Canadian justice system to punish drug lords and other high-level offenders.

"You don't have to set minimums that end up catching the little fish and sentencing them as though they are kingpins."

Bill C-10 has also come under fire from Canadians, including four former B.C. attorneys general, who earlier this month blamed marijuana prohibition for ongoing gang wars and an overburdened court system.

Shawn Atleo, national chief of the Assembly of First Nations, is also critical of the bill, saying that prevention and rehabilitation programs better serve Aboriginal Peoples, rather than jail time.

LEAP says it is baffled by the Harper government's decision to enact mandatory minimum sentences at a time when such measures are being repealed across the United States.

The letter also points out that 16 U.S. states, as well as the District of Columbia, have passed laws that allow for some medical use of marijuana, while 14 states have moved to decriminalize pot possession.

"We are individuals who were deeply involved with the war on drugs and have now accepted, due to our own experience and the clear evidence before us, that these policies are a costly failure," the letter goes on. "We changed our minds and we encourage you to do the same."

The group argues that taxation and regulation of marijuana "have the potential to dramatically improve community safety," in addition to raising tax revenue for cash-strapped governments and diverting law enforcement resources to where they can provide the most benefit.

Despite the opposition, a spokesperson for federal Justice Minister Rob Nicholson said the government is not looking at legalizing marijuana.

"Our government remains committed to ensuring criminals are held fully accountable for their actions, and that the safety and security of law-abiding Canadians come first in Canada's judicial system," Julie De Mambro said in an email to The Canadian Press.

Nicholson later told a Regina news conference he hasn't seen the letter from the U.S. group, but stands by mandatory minimum-sentencing legislation because it's "very targeted."

He said the legislation is a Canadian solution to Canadian issues and the government makes no apology for that.

Among those who have signed the letter are the former deputy chief of the Los Angeles Police Department, the former chief of the San Jose and Kansas City police departments and the former chief of the Seattle Police Department. Former detectives, customs and border protection agents, judges, prosecutors and corrections officials have also signed the letter.

With files from The Canadian Press