DENVER — Colorado Senate Republicans advanced legislation to repeal a Democrat-sponsored law that limits the size of ammunition magazines in response to mass shootings.

The 2013 law that bans the sale of ammunition magazines that hold more than 15 rounds passed when Democrats controlled both statehouse chambers. Republicans who regained a Senate majority in November for the first time in 10 years made repealing the law a priority and on Monday they gave initial OK to a bill to do so. A final vote as soon as this week will send the bill the Democrat-led House, which has already rejected an identical proposal.

Republicans argue the law is unenforceable and doesn’t improve public safety. But Democrats counter that the law makes it harder for mass shooters to get large-capacity magazines.