WESTFIELD — The City Council will meet Monday to decide whether to adopt a plan for downtown redevelopment.

The Grand Junction plan is the only business item for the meeting at City Hall, according to an agenda released today.

Grand Junction calls for major changes — including street expansions and extensive office, commercial and residential development — to the downtown area. Westfield would invest about $50 million in hopes of attracting $673 million in private development.

Westfield’s Advisory Plan Commission approved the plan 8-1 Monday. If the City Council approves the plan, the city’s comprehensive plan will be amended to include Grand Junction.

About 40 people attended the Plan Commission’s meeting and public hearing on the plan. Six people addressed the commission, and they offered mixed reactions. Two liked the plan but the other four were concerned about the plan’s feasibility.

Jim Anderson, co-chair of the group that authored the plan, assured the public the plan is just a concept and that nothing is finalized. Downtown will develop as the market allows, he said, so it could take 20 to 30 years to finish.

The only commissioner to vote against the plan was Russell Cameron. He had not seen enough of a financial or engineering plan to support Grand Junction.

“I didn’t think it was really ready, in a way,” he said. “Sometimes visions can be taken to the next step without regard to price.”