The UK government's communications privacy bill passed relatively smoothly through the House of Lords yesterday, with just one of the 51 amendments scheduled to be heard requiring a vote.

The single debated amendment to the Regulation of Investigatory Powers Bill was one which sought to tighten up a potential loophole regarding the circumstances in which decryption code keys can be demanded by law enforcement authorities. It was defeated by 132 votes to 118.

However, the government did not try to reverse two amendments it opposed last week over the costs involved in implementing the Bill, and said it would not require internet service providers (ISPs) devoted to the financial services industry to install the so-called black box email interceptors.

Concessions reported on Tuesday, including the right to sue law enforcement agencies for negligence should confidential material be leaked, were duly incorporated into the Bill, which has now completed its path through the Lords.

The significantly altered legislation now returns to the House of Commons to complete its last parliamentary stage before becoming law.

During its passage through the Lords, the Bill has been criticised - by peer and commoner alike - for being badly drafted, too expensive for ISPs to implement, technologically obsolete, damaging to ecommerce and potentially in violation of European Union human rights laws.

Critics have welcomed the changes made to the Bill, but it is still deeply unpopular with the IT industry and civil rights groups. Some ISPs have even threatened to quit the UK when it becomes law.

Speaking in the debate, Lord Cope, who has been leading opposition to the Bill, said: "We are sending back a very much better and improved Bill. We have rewritten large sections of [it]. We have redefined traffic data, we have provided for a technical advisory board to look after the technical difficulties of black boxes, and we have tightened up the provisions for the government to pay for those black boxes."