The Walsh administration abruptly canceled a planned door-knocking campaign by “volunteer” city workers yesterday after the Herald raised questions about the timing of the event just 2 1⁄2 weeks before Election Day.

Officials sent out an email last week asking staffers to volunteer for a “day of service” to knock on doors of targeted elderly residents in Mattapan and hand out brochures and other promotional materials.

The “connect-the-knocks” project — similar to door-to-door political canvassing of voters — amounted to what would have been a taxpayer-funded effort to promote Mayor Martin J. Walsh and his administration in the waning days of his re- election bid.

But the event, scheduled to kick off with Walsh yesterday morning, was unexpectedly canceled and moved to a later date in November — after the election.

City officials gave no explanation for the cancellation yesterday, declining to answer questions from the Herald.

The “day of service” would have allowed city staffers to work on the door-knocking campaign instead of their regular jobs.

Officials had said the project was an offshoot of the city’s “Age-Friendly Action Plan,” a document put out in May. The plan included an effort to target “potentially isolated” elderly residents who may have been unaware of the city services they could use. Those services include tax credits, property tax relief and elderly programs.

The city planned to give the residents — many of whom will be voting next month — a five-question survey, as well as materials on the services available to them.

Mattapan was picked for the launch of the project because it has a heavy concentration of older residents and those who speak Haitian and Spanish, officials said.

The planned door-knocking project was just one of a slew of “official” events Walsh has been participating in during the closing weeks of his race against City Councilor Tito Jackson. The mayor has made few actual campaign appearances while keeping up a full schedule of official events, highlighting the incumbency edge he enjoys against Jackson.

Just in the last few days, Walsh has attended a groundbreaking for a downtown project, a grand opening of a school and a ribbon-cutting for a health care center in Charlestown. He also spoke at a birthday celebration for civil rights activist Mel King in Roxbury.

Walsh yesterday unveiled Boston’s bid to attract Amazon’s new headquarters, giving him a showcase to promote the city.

During the same period, Walsh had no scheduled campaign events, even though Election Day is Nov. 7.