A group of US insurers has tried to rebut claims that a proposed change in US tax law would cost American consumers billions of dollars in increased insurance premiums.

The Coalition for a Domestic Insurance Industry claimed the Brattle Group report, sponsored by groups of non-US insurers including the Association of Bermuda Insurers and Reinsurers and authored by economic and insurance industry experts, was part of "an aggressive misinformation campaign".

The report said enactment of the bill proposed by Democrat Congressman Richard Neal, which would effectively raise US taxes paid by many non-US insurers, would cost policyholders between $10 billion and $12 billion in higher premiums.

One Washington source told The Royal Gazette that the Neal bill could be introduced next week.

The Coalition, which has long said it is fighting for "a level playing field" in competition with non-US insurers, produced a report of its own, putting a case that the legislation will have no impact on reinsurance capacity.

The report argues that "offshore companies continue to exploit their tax advantage, attracting capital to acquire US companies".

And it found that since Hurricane Katrina in 2005, the insurance sector has raised over $30 billion of new capital, the lion's share going to offshore companies.

"Foreign insurers have mounted an aggressive campaign to preserve this loophole and their unfair competitive advantage," Coalition spokesman William Berkley said. "Opponents have created a smokescreen of misinformation and scare tactics that grossly overstate the impact of the legislation on the US insurance market. The report issued today completely rebuts the opposition's manufactured arguments."