BOSTON (AP) — Opponents of expanding a natural gas pipeline through northwestern Massachusetts rallied on Boston Common on Wednesday, asking Gov. Deval Patrick to rescind his support for a new tax on New Englanders’ electricity bills to help subsidize it.

The protest, attended by hundreds of supporters, was the culmination of a month-long “rolling rally” that marched through towns likely impacted by the proposed 250-mile long pipeline expansion in Berkshire, Worcester and Franklin counties.