The last days of this dreadful government are being accompanied by an attack on rights and privacy that seems unprecedented during Labour's 13-year rule.

The government is now drawing up plans to amend the Postal Services Act to allow tax inspectors to intercept and open people's mail before it is delivered. Given the state's ambitions to collect all communications data this is hardly surprising, but we must ask ourselves how many more rights are seized by government and its agencies before Britain becomes the GDR's most obvious European imitator.

Currently postal workers have the right to intercept suspicious letters and packages and pass them to HM Revenue & Customs (HMRC) and then at an agreed moment the item is opened in front of the addressee. The change in the law will mean that HMRC will be able to open whatever it likes without the addressee being present or being made aware of the interception.

As usual, the government and HMRC public relations people underplay the wide-ranging and dangerous nature of this proposal by insisting that the new measure is simply designed to deal with the problem of tobacco smuggling. But the change, disclosed in a document published with the budget, means that HMRC will be able to trawl through private mail pretty much at will.

Quoted in the Daily Telegraph, Heather Taylor, a senior tax partner at Grant Thornton, said: "This seems like a very small and limited change, but it could be a very big step for increased powers HMRC. Once new powers are in the hands of HMRC they tend to be extended."

This is a very alarming development, and it is worth remembering who the HMRC employees work for and who is paying the bills for the enormous waste of money by government that, together with the attack on democratic rights, is one of the dominant features of the last 13 years. They work for us, the taxpayers – British citizens who are now to be relegated to the units of control familiar to the East German authorities.

Years ago I found myself in a dismal room at the Stasi headquarters in the East German town of Leipzig and saw the piles of opened mail left by Stasi officers when the Berlin Wall came down. There was a pulping machine, adapted from a piece of agricultural machinery, which had been hastily used to destroy the evidence of the massive programme of interception. It was an impressive sight and to me a lasting symbol of the East German dictatorship.

It seems extraordinary that we are about to allow the exact same type of interception to be established in Britain with such little complaint. How long will it be before we protest? Where is the political leadership needed to assert that these sorts of laws are unacceptable in a democracy? And for Pete's sake, how does the government square the measure with the rights to privacy "guaranteed" by its own Human Rights Act?