The eight civil rights group expressed their worry that millions, including those on low income as well as minorities, could be excluded from the vote for the presidency and for members of Congress.
They raised the issues during a meeting on Tuesday in Washington with representatives from the Organisation of Security and Co-operation in Europe (OSCE), which represents 56 states in Europe, Central Asia and North America.
The OSCE is likely to refer to the concerns in an interim report on the US elections out at the end of next week. It is also expected to pass on the views of the civil rights groups to its team of international observers who are being sent to monitor elections in 40 states.
The OSCE opened its observer mission in the US on October 9, led by OSCE ambassador Daan Everts. It has 13 international experts based in DC and 44 long-term observers from 23 countries being deployed throughout the country.
