BT may soon be facing its first national strike in 23 years after trade union leaders rejected an improved pay offer.
The Communication Workers Union (CWU) said was "no material change" in BT's revised pay deal.
A strike could disrupt BT's phone and broadband services because most CWU members are network engineers or call centre staff who deal with faults.
The CWU wants a 5% pay rise for its 55,000 members at BT after the company froze all pay for all workers last year.
BT is offering only a 2% rise this year and tried to sweeten the deal by saying the increase would be backdated to January and promising a 3% increase for 2011.
BT also pledged not to make any compulsory redundancies in 2010 and 2011, and to increase job opportunities in the UK by cutting back on overseas call centres.
The CWU has rejected the offer, but said it is willing to hold further talks.
The union said the offer was unacceptable in the light of the larger salary increases and bonuses for senior executives.
The CWU said BT made in excess of £1bn profit last year and exceeded forecasts by doubling its free cash-flow to £1.9bn while making £1.75bn in cost savings.
"We are asking for a fair and affordable share of BT's success. If it is good enough for the executives it is good enough for the staff," Andy Kerr, CWU deputy general secretary said last week.
Ian Livingston, BT's chief executive has opted for a 2% increase this year after receiving a £1.2m bonus for restoring the company to profit.
BT has also indicated that it is willing to continue talks with the CWU, although it expressed disappointment at the rejection of the revised offer.