For the first time in eight years, Timothy J. Toomey won’t be alone on the ballot in the 26th Middlesex District.

This year the state legislator, who represents eastern portions of Somerville and Cambridge and also sits on the Cambridge City Council, faces a challenge from upstart Green Party candidate Paul Lachelier.

Toomey’s campaign stresses his experience—he’s been in the assembly since 1992 and chairs its public safety committee. He says years of service will prove an asset as the legislature works to balance a tight state budget.

“We need to have someone there who’s been through this before,” Toomey says.

But Lachelier sees Toomey’s long tenure quite differently.

“It is time for a change,” he says. “We need some fresh blood.”

The French-born Lachelier has conducted a campaign centered on what he calls “a fair economy, a green community, a real democracy.”

Among other proposals, he favors a “maximum wage” to address wealth inequity in the United States. He supports a “green tax” to be levied on gas-guzzling vehicles like SUVs and full tax credits for people who buy bikes. He advocates sweeping campaign finance reform and supports restoring the vote to ex-felons.

Lachelier says his message has steadily caught on among young voters and says he’s now branching out to conservatives.

Lachelier accuses the state legislature of being immobilized by “inertia” due to its lopsided composition—fully 85 percent of the assembly is Democratic.

And he challenges Toomey’s politics as too conservative.

“What we have here is a Republican in Democratic cloak,” Lachelier says. “In this case, the Green is a better Democrat than the Democrat.”

Still, Toomey enjoys the support of major labor unions, including the Massachusetts Teachers Association and police and firefighters groups.

He dismisses any challenge to his progressivism, saying he is committed to building educational opportunities for working-class families.

And meanwhile, as Election Day approaches, Toomey says he is just “campaigning as usual.”

But Lachelier struggles to gain mainstream acceptance, taking what he calls a “one-on-one” approach with voters who may be wary of the unconventional Green Party agenda.

His supporters now include the Massachusetts chapters of the National Organization for Women, the National Abortion Rights Action League and the National Association of Social Workers.

Green Party are traditional long shots. If he does come out on top next week, Lachelier would be the second Green ever to win state office in the United States.

He says too many Green candidates have run symbolic campaigns—instead, he insists that he’s aiming to win votes.

“I’m one of those that thinks we should be running serious campaigns,” he says. “I think it’s going to be close.”