An arresting image of GCHQ – the government’s communications headquarters in Cheltenham – occupied the front page of the Times last week to inaugurate the paper’s unprecedented, but entirely controlled, access to the secret heart of Britain’s surveillance capability. It was accompanied by a headline using a James Bond title – For Your Eyes Only – together with some lines about spies “emerging from the shadows”.

It was all part of a propaganda push from the secret intelligence agencies before the announcement this week by Theresa May of new surveillance laws in the draft Investigatory Powers bill. Page after page of coverage followed over the next three days, praising the heroism and endearing normality of the people who work in intelligence and their uncomplicated desire to keep us all safe and free.

One GCHQ official was quoted as saying “GCHQ has to be out there. We can’t operate behind veils of secrecy any more,” a remark that will have certainly surprised Tory MP David Davis, the most consistent champion of liberty in parliament, who said of the propaganda effort: “These people won’t even answer a parliamentary question because of security issues.” But last week GCHQ was so out there that the spooks were practically making kiddie spy kits on daytime TV.

And it was all so alluring, what with access granted to the dark glamour of the GCHQ building and the happy coincidence of the latest release from the Bond franchise, Spectre, which, if nothing else, encourages the mythic fantasy of British spies girdling the world to fight evil and keep us safe.

Everything seemed set fair for the launch of the most invasive surveillance regime in the west. But then the reality check came. Whether it was prompted by the spectacle of the spooks taking their kit off in public, or the hard political realities following the defeat of the government in the Lords on tax credits, is not yet clear, but May appears to have bowed to pressure to drop some of the draft bill’s most controversial measures.

Gone is the proposal that communications service providers would be required to retain data that passes through their networks from companies based abroad. The former British ambassador to the US, Sir Nigel Sheinwald, who was deployed by David Cameron to sound out the US government on the bill, will almost certainly have reported American alarm. And foreign communications service providers will not have to meet the UK’s obligations on data retention, either.

One of the more alarming aspects of last week’s coverage was the news that police had demanded the power to view the internet browsing history of everyone in the country, also published by the Times. They argued that communications providers should retain everyone’s data for a year, which, given reported abuse of police databases and the automatic number recognition system that tracks vehicle movements, was extremely worrying. But that idea has been ruled out by No 10. More important to the tech industry is the news that the government has categorically ruled out proposals to ban encryption.

Facebook Twitter Pinterest Edward Snowden Photograph: Alan Rusbridger/The Observer

Baroness Shields confirmed this in the Lords last week, but it would in any case have been impossible for the government to insist that such companies as Facebook and Google would either have to abandon encryption or provide a back door. Frankly, the idea was hopelessly impractical and the government is making a virtue out of necessity. Nevertheless, there seems to have been a slight change in the government’s tone, which is in contrast to headbangers at the Home Office, which has long nurtured plans for a new bill since the snooper’s charter – the baby of, among others, the former spy Charles Farr – was abandoned after Lib Dem opposition during the coalition government. What this says about relations between May and senior cabinet figures is interesting. George Osborne and Boris Johnson both regard her as a threat to their leadership ambitions and she will never receive much support from her old foe Michael Gove.

The correction from No 10 also includes a reaction to two recent news stories, concerning the exclusion of MPs’ communications from surveillance under the Wilson doctrine, which was ruled by a court not to have any basis in law, and the protection of journalists’ sources, which came to the fore when a Newsnight reporter’s computer was seized by police using terror laws. Both MPs and journalists are going to receive specific exemptions.

“We know these powers are needed as technology changes and terrorists and criminals use ever more sophisticated ways to communicate,” said a government spokesman. “But we need to give people the reassurance that not only are they [new powers] needed, but that they are only ever used in a necessary, proportionate and accountable way.” This statement is certainly welcome but we should not relax. We are about to enter the totally connected future of the internet of things, when data about each one us will pour from connected TVs, cars, burglar alarms and heating systems, CCTV, fitness monitors and voice-commanded devices like Amazon’s Echo.

The bill will certainly seek to establish the right to mass surveillance – not just bulk collection but the interception of individual communications and the suborning of people’s devices and computers with malware – what is known in the trade as CNE, or computer network exploitation. (This means taking over the device and monitoring the geolocation, texts, emails, calls, internet connections and images recorded by the camera of a phone, or other device, in real time). The crucial part of all this is the interception of traffic on internet cables, revealed by Edward Snowden. It is difficult to see GCHQ giving up that dependency lightly.

Even with these new adjustments, the bill will contain measures that are worryingly intrusive. Whatever the agencies say about our safety, the threats of hacking, cyber warfare, terrorism and paedophilia – all of them incontestably real – this is also a struggle for the private sphere and how much unseen access we let into our lives. The onus will be on MPs to respond to their constituents’ need to be safe from a prying state, as well as numerous hostile forces. A great propaganda push is about to hit them in the form of private briefings from the agencies, and for all our sakes they should resist the breathless swoon of the Times man in GCHQ.

The other upside of the debate is the chance to address our chaotic interception laws. In an influential report of the summer – praised by No 10 – Britain’s reviewer of terrorism laws, David Anderson QC, said: “Ripa [Regulation of Investigatory Powers Act 2000], obscure since its inception, has been patched up so many times as to make it incomprehensible to all but a tiny band of initiates … This state of affairs is undemocratic, unnecessary and – in the long run – intolerable.” The government has responded to Anderson’s suggestion that the numerous and often ineffectual parts of the oversight regime will be replaced by one investigatory powers commissioner, a role that will be filled by a senior judge.

The devil will be in the detail and legislators who opposed the snooper’s charter are worried about what the Home Office will try to sneak past them.

When the joint committee of peers and MPs forms this week to examine the draft bill, one of the really big issues considered will be the absence of judges from the process of authorising interceptions.

We can assume that May intends to retain that power since no mention has been made of it this weekend. Currently 2,500 authorisations are made every year – that is about 10 warrants every working day, an impossible load if each one involves at least an hour’s consideration, which it should. Davis advocates a panel of between 20 and 30 judges to do the job.

Only about eight weeks of parliamentary time have been allotted for consideration of a vast and complex bill by the joint committee, which has yet to get a chair. The discussion will be dry as dust but we cannot ignore it. Not for the first time in the last decade, our liberty depends on the conscience of legislators and our close attention.