Launching a report on unions and the voluntary sector, he will say that charities "believe in employee consultation and partnership, not confrontation and threats".
Bubb's remarks come days after RSPCA staff came within eight votes of sanctioning strike action for the first time in the charity's history in a ballot by Amicus.
But members of the union did, by 292 votes to 155, support industrial action, which could include an overtime ban or refusal to cover for absent staff.
Bubb told Third Sector that the RSPCA's experience demonstrated that strike action was inappropriate: "Not only is it against the ethos of the sector, it could be very dangerous to the long-term viability of a charity, hitting its reputation and fundraising potential."
He said unions should not have a veto when charities were forced to make redundancies, nor should they "patronise charity staff by telling them they are exploited".
But Chris Ball, national voluntary sector secretary with Amicus, said his comments were "a mixture of unexceptional homilies and irritating generalisations that can never be universally true.
"We are as interested in partnership as anyone, and were practising it in charities like Save the Children years before it became a vogue.
"Of course some charities exploit their workers and those that do deserve to be criticised. We almost never have strikes in charities but those few that do occur are short and over the most telling issues."
The RSPCA strike ballot was held because of plans to axe 200 jobs through the closure of ten regional call centres. The animal charity has to make savings of £8m because of a crisis caused by a fall in the value of its investments.
Ball accused the RSPCA of making the crisis worse by failing to ask for more support from the Government for extra work resulting from the foot and mouth crisis and the Wild Mammals Protection Act. "Because of their self-denial, jobs and services will be lost," said Ball.
An RSPCA spokeswoman said that was a "red herring". The charity had made a policy decision not to accept money from government to maintain its independence.
See They Said It, p2.