A council order that bans begging will be challenged in the High Court.
The public space protection order - or PSPO - brought in by the former Poole Council bans begging and leaving items like bedding unattended.
Opponents, who say the Poole order unlawfully targets rough sleepers, have raised funds to bring the challenge.
The case against Bournemouth, Christchurch and Poole Council, brought by chairman of Poole Labour Party, Sarah Ward, will be heard on 26 March.
Ms Ward previously described the ban as "ludicrous", saying it was "never going to be the answer to help rough sleepers and tackle homelessness", according to the Local Democracy Reporting Service.
More than 4,500 people signed a petition against the PSPO, which allows officers to issue £100 fines to anyone caught begging in parts of the town centre.
At the time, Borough of Poole council said the fines aimed to "tackle behaviours that are causing concern and distress to people in the town centre, such as aggressive begging, street drinking".