Matt O'Connor believes that while the superhero stunts gained great publicity for the cause, they were in danger of becoming a parody of themselves.
He is also concerned at the number of people who hijacked the Fathers 4 Justice logos and used it for their own cause.
The next big campaign from the group will see its 12,000 members being encouraged to support the call for overnight staying contact.
Fathers will put pressure on the Children's Minister Beverly Hughes ahead of October's parliamentary debate on family law reform.
They hope sending pyjamas to London will highlight the fact that many separated fathers do not see their children for overnight stays.
The new campaign follows proposals made by Fathers 4 Justice to the Court Welfare Service (Cafcass) to make overnight stays the minimum recommended parenting time.
Members are encouraged to include details of their individual cases when they send pyjamas to the Children's Minister.
A fleet of motorised beds will also hit the M25 as part of the campaign, along with a bed in a perspex box in Central London.
The beds can travel at 70 miles per hour and are completely legal and roadworthy.
On the night of October 20, Fathers 4 Justice members will stage an overnight protest outside the offices of the Department for Education and Skills before a "Bedlam" protest in Central London with thousands of men in pyjamas marching through the West End pushing beds to Whitehall.
Protesters taking part are urged to register for the march beforehand.
In keeping with the sleepover theme, thousands of alarm clocks will go off outside the DfES office where the group will hold a rally.
Matt O'Connor said: "We need to keep the pressure on.
"Cafcass have until September to wake up and start making genuine and meaningful progress with regard to family law reform.
"And overnight staying contact is at the very heart of what our campaign is about.
"We want MPs talking about the issue in parliament.
"The public need to be aware of what is going on and the kind of reform that is needed.
"This campaign will be something surreal and will keep disruption to a minimum." For further information about Fathers 4 Justice and the pyjama protest visit www.fathers-4-justice.org.