A new poll from the League of Conservation Voters, which is supporting Rep. Ed Markey in the Massachusetts Senate special election, shows him with a double-digit lead in the Democratic primary.

The poll, by respected Democratic pollster Geoff Garin, shows Markey at 42 percent and Rep. Stephen Lynch at 28 percent.

Markey is slightly better-known and better liked among the Democratic primary electorate, according to the poll, but both men remain unknown to at least half of voters, meaning there is plenty of room for movement. But among those who know both men, Markey leads 52 percent to 32 percent.

All early polling has shown Markey with a lead, and Markey also has the backing of the Democratic establishment. The primary is set for April 30, with whoever wins being a strong favorite to win the old Senate seat of Secretary of State John Kerry (D-Mass.).