US legislation designed to ensure online retailers pay the same taxes as shops on the high street has passed its first stage in the Senate, but faces strong opposition before passing into law.

This week, senators voted 70 to 24 in favour of the Marketplace Fairness Act, which would give states the power to require internet-based retailers with sales over $1m (£646,000) to collect state and local sales taxes due on online purchases.

If passed, the legislation would overturn a 1992 supreme court ruling that said a state could not force a retailer to collect sales tax unless the retailer had a physical presence in the state.

In most instances, consumers are not paying sales tax on items bought online, which conventional retailers say discriminates against traditional 'bricks and mortar' stores.

The proposed legislation is backed by Barack Obama and has cross-party support, as well as the backing of online retailer Amazon, which has distribution centres in several states.

The largest online opponent is eBay, which has campaigned against the bill and organised a mass protest by its sellers.

The proposals are also likely to come under intense scrutiny at the next stage, in the House of Representatives, which is opposed to any tax increases.