Opponents of an expansion project at Boston Children's Hospital have lost their latest attempt to block construction.

A Suffolk Superior Court judge on Wednesday denied the group's request for an injunction to halt construction of a new $1 billion clinical building, which will result in the demolition of Prouty Garden — a half-acre healing garden bestowed to the hospital by a donor in 1956.

The attorney for the opponents, Greg McGregor, argued that the state Department of Public Health failed to properly consider the project's impacts — including the loss of Prouty Garden — when it recently approved the plan. The garden is used by patients, family members and staff for respite and contact with nature.

"Prouty Garden is a medical facility. It's of value for therapeutic purposes in medicine," McGregor said after the hearing. "All eyes are on the hospital. Everybody will be looking to see whether it barges full steam ahead."

Boston Children's Hospital officials have said they plan to close Prouty Garden within the next several weeks. In a statement Wednesday, a hospital spokesman said administrators are pleased with the court's decision to not delay construction.

"Throughout the multiyear process, the health needs of the children we care for have been our focus," the statement read.

Opponents still have legal challenges pending in court: an earlier lawsuit and an appeal of the Department of Public Health's approval of the project.