The nearly month-long strike at the Toronto Zoo may be coming to an end.

CUPE Local 1600 and the Toronto Zoo say they have reached a tentative agreement, which, if ratified, could see the zoo open next week, management says.

The deal was made early Thursday morning after nearly 24 hours of continuous negotiations, according to CUPE.

More than 400 union workers had been on strike since May 11, citing concerns over job security.

Details of the new agreement will not be released until union members ratify the deal.

"We believe this tentative agreement is fair, reasonable and acknowledges the unique work that is done at the zoo," Toronto Zoo management said in a statement.

The zoo has been closed for the duration of the strike. Its roughly 5,000 animals have been cared for by a group of employees exempt from the job action.

The union local had expressed concerns that those caretakers were unable to properly look after the animals, potentially jeopardizing animal welfare and breeding programs.

Toronto Zoo management, however, disputed those claims.

"The animals continued to receive excellent care and our critical conservation programs were not impacted by the strike," according to the zoo.

If the deal is ratified, zoo management says it will take between 24 and 48 hours to assess when it can reopen.

"We're hoping that we'll be able to open up the zoo at some point next week," said Toronto Zoo spokesperson Jennifer Tracey.