And he "really worries" for those who don't.
McGregor said this has put clients at real risk and that they hadn't received much communication from the board - except for when his boss told him what the board had said.
"The next steps are to consider the legal alternatives because this will be an unethical disengagement from supply and support to clients. And possibly raising it with health and disability."
He said his staff were effectively being asked to take a position in what will be neglect rather than a smooth handover in the safety of the client.
"We know we have funding, so this isn't a financial issue, we have leases that go into next year. So in theory trusts can't be wound up until the leases expire."
Some staff, McGregor said, had began setting up another company, but it wouldn't be a charity so many clients would remain vulnerable.
Chief executive Richard Jeffrey this year told the Herald requests for the organisation's help have grown 280 per cent over the past few years.
In 2018 they had 139 inquiries, and last year 567 sought help, 180 of those were people seeking ACC support.
The Wellington City Council announced $400,000 more funding would be given per year to sexual violence charities in the capital.
Councillor Tamatha Paul said it was extremely disappointing Mosaic was closing and it was a "big hit" for survivors everywhere.
"It's awful, Mosaic's stood alone in being a support service for men, who we know experience sexual harm as well."
The board said it was working closely with the chief executive to wind up Mosaic operations as smoothly as possible, with the wellbeing of staff, clients and volunteers top of mind.
"We would like to thank the staff and other supporters for their commitment to Mosaic and wish every success to the staff embarking on a new journey to support Kiwi men through their new organisation: Men and Trauma."
The board was asked why the decision was made, but this was not addressed and chairwoman Carrie Buckmaster said they would not be making any further statements.
"Ongoing peer support services are available to male survivors in the Wellington region
through the Road Forward Trust, a Male Survivors Aotearoa affiliated and approved service."
Where to get help:
• 0800 543 354 (0800 LIFELINE) or free text 4357 (HELP) (available 24/7)
• https://www.lifeline.org.nz/services/suicide-crisis-helpline
• YOUTHLINE: 0800 376 633
• NEED TO TALK? Free call or text 1737 (available 24/7)
• KIDSLINE: 0800 543 754 (available 24/7)
• WHATSUP: 0800 942 8787 (1pm to 11pm)
• DEPRESSION HELPLINE: 0800 111 757 or TEXT 4202
• NATIONAL ANXIETY 24 HR HELPLINE: 0800 269 4389If it is an emergency and you feel like you or someone else is at risk, call 111.
