The home secretary has launched a barely veiled attack on Nick Clegg over the Liberal Democrats' sceptical approach to plans to give the police and security services powers to track all mobile phone and internet use.

In an article in the Sun, criticised by a Lib Dem MP as "bizarre", Theresa May said "we could see people dying" if her draft communications data bill was blocked by parliament.

Clegg warned David Cameron last week that Lib Dem support for the legislation, dubbed a "snoopers charter", depended on the concerns of a special parliamentary scrutiny committee being met.

The pre-legislative scrutiny report from the joint committee of MPs and peers was expected to be published on Tuesday but has been delayed for a week amid conflict over the government's response. A separate report from senior MPs and peers on the parliamentary intelligence and security committee is also due to be published.

The home secretary's comments to the Sun reveal the depth of coalition tensions over the plan for phone and internet companies to retain their records for 12 months. The police and security services are to be given on-demand access when tracking terrorism suspects and serious criminals.

May told the Sun: "It is not snooping. It is absolutely not government wanting to read everybody's emails – we will not be looking at every webpage everybody has looked at.

"The people who say they are against the bill need to look at victims of serious crime, terrorism and child sex offences in the eye and tell them why they're not prepared to give the police the powers they need to protect the public. Anybody who is against this bill is putting politics before people's lives."

She claimed that without the powers criminals would walk free and paedophiles would remain unidentified: "It is a question of whose side you are on," she added.

The Lib Dem MP Julian Huppert, who served on the scrutiny committee looking at the detail of the draft legislation, tweeted that May's comments were "bizarre".

It is widely expected that the scrutiny committee, chaired by the Conservative former home office minister Lord Blencathra, will at the very least demand that the draft legislation be substantially rewritten. The concerns of MPs and peers centre on the lack of privacy safeguards, the potential £1.8bn cost, and the lack of clarity over what the police and security services will do with such confidential personal data.

Huppert, the Lib Dem home affairs spokesman, said in September the party would not allow the bill to go forward in its present form. "The major problem was with the clause that gives the home secretary virtually unbridled power to snoop on somebody's internet activity," he said.

May also faces criticism from the Tory libertarian right, with some Conservative MPs such as Dominic Raab declaring they would not vote for the measure.