The EU Directive on Gender Equality will outlaw discrimination in the provision of financial services on grounds of sex.
If the proposals are brought into force, it would be illegal for motor insurance companies to take gender into account when pricing premiums.
The move has been greeted with outrage by the insurance industry, which has warned that all road users are likely to face increased premiums if the proposals come into effect.
However, they say that women drivers aged between 17 and 24, and older male motorists are likely to be hit hardest.
Under current practice, UK insurers treat men and women drivers differently. Although female drivers have more accidents than their male counterparts, they tend to be at a lower speed. This means that overall, women claim far less money from insurers than do men, who are more likely to be involved in high-speed crashes.
In recognition of this, insurers charge women lower premiums than men.
According to Direct Line, Britain’s biggest motor insurer, the average policy for a 17-year-old male now costs 1,951.95 a year. A girl of the same age would pay an average of 1,293.60. Direct Line suggests that under the new directive, the adjusted figure for both groups would be more than 1,700 - a rise of around 500 for young women.
At the other end of the age scale, older male drivers are statistically the safer sex on the road, and are consequently charged an average 135 less than their female contemporaries.
However, young women and older men face losing these advantages with the EU Directive on Gender Equality, which is due to be considered by the EU Council of Ministers on 1 June.
Devised by Anna Diamantopolou, the Commissioner for Employment and Social Affairs, it aims to eradicate discrimination on grounds of sex across the financial services sector, which also has implications for life pensions and health cover.
Ms Diamantopolou said: "This is a groundbreaking proposal. This would establish a public policy decision that gender discrimination in the access to and supply of goods and services is unacceptable."
But a spokeswoman for the Association of British Insurers (ABI) said that while the industry body supports the Directive's aim of outlawing unfair sex discrimination, it should think twice about the implications for motorists.
A spokeswoman for the ABI said: "The use of gender as a factor by the insurance industry is objective, and based on sound data. If gender were excluded, the use of lifestyle factors would produce less accurate projections, and add considerably to the cost.
"Gender is used as a factor in assessing premiums, along with the type of car, its use, and the postcode. Reasonably enough, young women pay about 25% less for their insurance than young men."
The ABI warned that the changes would mean higher prices for almost all road users.
Its spokeswoman added: "Young female drivers would pay more for their vehicle insurance. Unisex prices would be closer to the higher, male level."
The AA backs the ABI’s stance. A spokesman for the motoring organisation, said: "It is only fair that people pay for the risk they represent. It is unfair that you should have to foot the bill for those who represent a higher risk than you do."