Here is what a dissapointed union said:
"The ballot has been cancelled following legal advice which clearly outlined that under the notoriously restrictive trade union laws in the UK certain technical breaches would potentially invalidate the ballot. CWU has today received an offer from BT to meet for further negotiations and the union will take up that offer whilst taking all necessary steps to allow a re-ballot as soon as practically possible if negotiations are unsuccessful."
Andy Kerr, CWU deputy general secretary, said: "We're bitterly disappointed that this ballot has had to be cancelled. It's devastating for our members and for trade union rights in the UK and of course it doesn't help to resolve the outstanding issues over pay which we have with BT.
"The legal technicalities on which this ballot has been cancelled again raise questions over the right to strike and the extremely restrictive trade union laws that exist in the UK. The law, in our view, appears to be outdated when it comes to the provision of information.
"We will take all necessary steps to allow us to re-ballot our members as soon as is practically possible. In the meantime we will also be taking up an offer from BT for a meeting to see if there is a way to resolve this dispute without the need for industrial action."
CWU said it has received a series of letters from BT over the past few weeks which effectively amount to a legal challenge. On taking legal advice regarding the questions put to the union by BT the decision to cancel the ballot was taken on Monday 5th July.