The Association of Greater Manchester Authorities (AGMA) must persuade all 10 of its authorities to accept the TIF proposals, which would put £2.8bn of transport improvements into action, but also introduce congestion charging that could coast commuters up to £5 per day.
However, at the launch last month, Manchester Council leader Sir Richard Leese said a two-thirds majority vote may be sufficient to carry the TIF plans, although this was by no means certain as three councils - Bury, Stockport and Trafford are opposed, and Bolton has already proposed a referendum to decide which way it will vote.
Last week, Manchester City Council voted unanimously in favour of a referendum on the TIF bid, after the three-month consultation.
Sir Richard Leese said all 10 AGMA members should agree to be bound by the result.
AGMA Leader Lord Peter Smith, said: "We hope to make a decision which all authorities will support on a referendum next month when AGMA reconvenes.
"The formal consultation starts on the 7th July and I would urge everyone to carefully read the information packs which will be sent out to every household in Greater Manchester over the next few weeks and to visit the touring exhibition, to ensure they are fully informed about the proposals."
Any referendum would follow the public consultation, which ends on October 10.
The meeting of the Executive Committee in Swinton, earlier today, also noted a separate proposal to consult on a 100% discount to apply to private hire taxis.