Privacy campaigners are frantically trying to brief MPs about the implications of the data retention and investigatory powers bill (Drip), before it is forced through all of its Commons stages tomorrow.

The more experts look at the bill, the more convinced they've become that it provides authorities with the spine of the snoopers' charter, but without any of the public debate or parliamentary scrutiny which were supposed to accompany it.

The charter – known as the draft communications bill before it was killed off – would have forced internet service providers and mobile operators to keep details of their customers' behaviour for 12 months.

Analysis of Drip, which was supposed to only extend the government's current powers for another two years, suggests it forces through many of those requirements on internet firms without any of the political outrage which derailed the earlier effort.

Clause four of the bill appears to extend Ripa – the Regulation of Investigatory Powers Act (basically Britain's Patriot Act) – so that the UK government can impose severe penalties on companies overseas that refuse to comply with interception warrants. It also lays out situations in which they may be required to maintain permanent interception capacity.

Clause five then provides a new definition of "telecommunications service", which includes companies offering internet-based services. That seems to drag services like Gmail and Hotmail into the law, and very probably social media sites like Facebook too.

The government insists the extraterritoriality clause merely makes explicit what was previously implicit. It's tosh. As the explanatory notes for the legislation - released very quietly on Friday night – make clear, overseas telecommunications companies did not believe they were necessarily under Ripa's jurisdiction.

"Regarding the amendments to Ripa, in view of the suggestion by overseas telecommunications service providers that the extra-territorial effect of Ripa is unclear, it is considered necessary to amend the legislation to put the issue beyond doubt," it reads.

"This includes clarifying the definition of a 'telecommunications service' to ensure the full range of telecommunications services available to customers in the United Kingdom are included in the definition."

David Cameron, Nick Clegg and Ed Miliband insist Drip merely extends their current powers for two years. That's nonsense. These two clauses, which have nothing to do with the purported aim of the bill, provide the spine of the snoopers' charter.

They also appear to provide a legal basis for programmes like Tempora, the project revealed by Edward Snowden to allow GCHQ to tap into transatlantic fibre-optic cables and stored data.

Notably, Privacy International, Liberty and others are taking the government to a tribunal this week on whether Tempora is legal, even though the government won't even admit its existence. Drip could make the tribunal ruling irrelevant.

Snowden himself issued a savage attack against Drip and the way it was introduced in a Guardian interview from Moscow.

"I mean the NSA could have written this draft," he said. "They passed it under the same sort of emergency justification. They said we would be at risk. They said companies will no longer cooperate with us."

"And yet suddenly we're told there's a brand new bill that looks like it was written by the National Security Agency that has to be passed in the same manner that a surveillance bill in the United States was passed in 2007, and it has to happen now.

"And we don't have time to debate it, despite the fact that this was not a priority, this was not an issue that needed to be discussed at all, for an entire year. It defies belief."

The explanatory notes show who is entitled to consultation and who is not.

"Due to the pressing nature of this legislation a limited process of consultation has been completed with those affected by the provisions, including the communications industry, and law enforcement and intelligence agencies," it reads.

Who has not been consulted? Well, MPs for a start. They are being coerced into supporting this vague and dangerous bit of law without being able to scrutinise it.

"Given the need to ensure that law enforcement agencies are able to retain their capabilities, extending the timetable for parliamentary scrutiny is not possible in this instance," it reads.

"Due to time constraints the home affairs select committee has not had an opportunity to scrutinise the legislation."

And of course the other people not being consulted are those affected by the bill: the public. There has been no debate, no consultation, to pretence of due process. And the secret deal between Cameron , Miliband and Clegg means voters who object to this stitch-up have no way of registering their protest at the general election via the main parties.

The explanatory notes also makes it clear which direction we are travelling in. By 2016, that great big debate on the snoopers' charter which Cameron is suddenly so keen on will take place. One does not need to guess the position the government – any government, run by any prime minister – will adopt.

"This bill does not enhance data retention powers, although it is envisaged that when communications data policy is considered in the next parliament, legislation conferring further powers may be proposed," it reads.

The snoopers' charter is being introduced in chunks. They lost the debate. Now they are smuggling it into law.

Drip will go through all of its Commons stages in one go tomorrow. It is a process which usually takes months.

Update 16:33 BST

Theresa May was asked about the new measures repeatedly by Lib Dem MP Julian Huppert at the home affairs committee today. He was not unsympathetic to her. Although usually on the other side of the fence, he's on board with what the government has proposed. But you could see him losing patience as the session wore on.

First he asked if she would inform the committee if she found that actually it turned out the measures in the bill do go further than current law. She refused to do so.

Then he asked if any firms had ever complied with an international request under Ripa. After all, if it was assumed to have international reach, surely at least one foreign firm would have been responded to a government request for interception. Huppert told the home secretary he didn't want individual names of firms, just confirmation there had been at least one instance. She ignored him. It is a favourite tactic of the home secretary to answer the questions she wishes she was asked.

"I'm not able to talk about specifics," she said. "We have consistently been of the view, as I assume has the previous government, that Ripa did have that extra-territoriality. That has been questioned. I want to put it beyond question."

Again, Huppert told her he was not asking for specific names, just confirmation that a least one non-UK firm had complied with a UK government Ripa request.

"I don't disclose who responds to warrants and I don't intend to give names and I don't intend to say anything which would lead people to try and identify names," May replied.

Even at this level, scrutiny is borderline impossible in the face of such refusal to give basic information.