VAT is expected to be cut on condoms and other contraceptives in Gordon Brown's Budget later this month, according to reports.
VAT is currently charged on contraceptives at 17.5%
High Street chemist Superdrug said it was so confident the Chancellor would reduce VAT from 17.5 to 5% that it had already cut the prices of its condoms.
It said the move followed a successful 10-month campaign.
But the Treasury would not confirm the reports, adding it never commented on Budgets before they were delivered.
Despite this, Superdrug claims it has it "on good authority" that VAT will be cut.
The move could also see the cost of over-the-counter emergency contraceptives or morning after pills fall from around £25 to £22.
Superdrug said its long-running campaign to reduce the price of contraceptives to help bring down teenage pregnancy rates and sexually transmitted infections had paid off.
Superdrug managing director Euan Sutherland said: "We are delighted that the Treasury has heeded calls to make a change in the VAT rules.
"The VAT rules do not make sense and this is just the first of a series of challenges we will mount to ensure our customers don't pay luxury tax on the items we know are real essentials."
Superdrug said the move would save consumers £5m on condoms alone.
It comes after 69 MPs signed an Early Day Motion in support of the campaign and a petition signed by 20,000 Superdrug customers was delivered to the Treasury along with 9,000 condoms.
A spokeswoman for the Family Planning Association said the changes were good news.
"Making condoms cheaper will obviously make them more accessible to more people.
"Sexually transmitted diseases and unplanned pregnancies are very high in the UK already so anything that can help make condoms and emergency contraceptives more accessible is welcome," she added.
Figures out last week showed attempts to reduce the teenage pregnancy rate were behind target despite a £150m campaign.
Reported cases of HIV and other sexually transmitted diseases are also on the rise.