A group of affordable housing activists spent over twenty hours — including, for some, an entire night — in front of Boston City Hall in protest of an anticipated vote to approve a development plan for Boston’s Roxbury and Jamaica Plain neighborhoods.

Going by the name “Keep It 100 For Real Affordable,” the group gathered in front of City Hall yesterday to hold a self-described “vigil” to demand that more affordable housing be included in a development plan currently before the Boston Planning and Development Agency (BPDA), formerly known as the Boston Redevelopment Authority.

The group, while not directly opposed to the planning process, has pushed since the planning process was announced for stronger affordability requirements and protections. 

The event was scheduled to last only a few hours. But some members of the group stayed, first attempting to erect tents  on City Hall Plaza and then, when they say police wouldn’t allow the tents, staying overnight without tents.

Thia Simon, who is 19, said that she and about 20 others spent the night huddled in sleeping bags after police told them they would not be allowed to erect tents.

Simon, whose parents immigrated to Boston from Haiti, said that she became involved in the group because of her family’s experiences with gentrification.

“It’s just been very hard to stay in one spot,” Simon said. “So much of my life I’ve been moving around. It’s so hard to lay down roots.”

The group has mobilized around attempting to persuade the BPDA not to approve the neighborhood plan without adding more stringent affordable housing requirements to it.

The plan, officially titled “Plan: JP/ROX,” lays out a vision for future development, zoning, and city planning, including plans for new housing.

As currently written, the plan describes as much as 40 percent of new housing as being “affordable” — although critics contest that many of those units still won’t be “affordable” at area income levels.

Members of the assembly yesterday called for more than fifty percent of new housing to be affordable, and for the city to re-evaluate its definitions of affordability.

Danielle Sommer, a lifelong resident of Roxbury and Jamaica Plain, and one of the organizers of the group pushing to change the development plan, told WGBH News today that the group does not oppose development generally.

“We know folks are going to come to our neighborhood — partially because residents invested a lot of time and energy into making it a great place to live,” said Sommer.

“We want to welcome new people — we just don’t want it to be at the expense of our own homes.”