yes they can and they don't need your permission either.
Also, loyalty cards (eg Nectar cards) already share the information with HMRC to cross reference your spending with your income tax to determine if you are spending more than you earn; Which therefore indicates that you are not declaring your full income and should be paying more income tax.
Also your medical records *will* be available to central government as everything is planned to be centralized ([...]to computerize all NHS patients' records, originally estimated to cost £2.3 billion over three years but the cost of which has grown to £12.7 billion).
you can "opt out" but you will have to pay to opt out and to maintain your paper records.
A problem the government has is the interfacing of records across different sources effectively...
"[...] costing the taxpayer almost as much as the autumn bank bailout. But the huge amounts being spent by the Government on information technology — £16 billion this financial year — are barely noticed.
With no central regulation by one ministry, civil servants enter into contracts worth billions with a few select companies.
The details are protected by confidentiality agreements and periodic progress reviews in Whitehall are kept private, despite calls by MPs and anti-privacy campaigners for their disclosure.
The cost of most large projects balloons. The Government admits that only about 30 per cent are completed on time and on budget.
An investigation shows that the overrun of the largest IT projects totals £18.6 billion."
The government remains committed to try any aspect to garner as much data on the populace as possible with the ID card scheme an attempt to provide a central source of data on the populace, not for immigration or security but to enhance the ability to increase taxation capacity.
"Mr Johnson said the ID card scheme was still very much alive "
Spartacan is is correct, the government continues to face ever diminishing support and lack of financial capability, yet it needs more taxation revenue to resolve the very problems it created.
It seems to me that the whole country could be falling for a devilish piece of spin. They know people don't like ID Cards but have little concept of the NIR. It looks like the Government will get exactly what it wants - an Register linked to a passport. All they will have to do is start making the passport a designated document for a range of purposes. They will still be able link the major events of your life to a central register. The difference is that this is somewhat harder to campaign against!
This government had as it's election policy a referendum, yet denied the electorate it's very own election pledge on basis of a different title.