MPs are to debate the government's Protection of Freedoms bill later, which ministers claim will protect millions of people in England and Wales "from unwarranted state intrusion in their private lives".
It is a very wide ranging piece of legislation, which is meant to fulfil Conservative and Lib Dem election pledges to scrap laws introduced by Labour which they believed were damaging civil liberties.
But Labour say the planned changes go too far in some areas, such as the DNA database, and child protection charities are concerned about possible loopholes in planned new vetting procedures.
Here is a guide to 12 key areas in which the law is set to change:
The DNA database
The old system: DNA could be kept indefinitely by police, even if someone had been arrested but not charged or found not guilty.
The new system: Under the new scheme DNA profiles for those arrested or charged with a minor offence will be destroyed if they are not convicted. The vast majority of the one million people on the DNA database who have been arrested but not convicted of a crime will be removed from it within months of the bill becoming law.
Where someone has been charged with a serious crime but not convicted, their DNA profile will be held for three years with a possible two-year extension with court approval.
Police will however retain the right to keep DNA of people deemed to be a risk to national security, even if they have not been convicted of an offence.
Shadow Home Secretary Yvette Cooper has said that the government is going "too far" on DNA retention and accused them of "ignoring expert advice that has a significant impact bringing serious criminals to justice and exonerating innocent people".
The old system: Terrorist suspects could be held for a maximum of 28 days without charge.
The new system: This period will be permanently reduced to 14 days.
The coalition has already allowed 28-day detention to lapse by not putting an annual renewal vote to Parliament. The system has therefore reverted to 14 days detention without charge for terror suspects. This bill will make that change permanent.
The old system: Following the murders of Holly Wells and Jessica Chapman by Ian Huntley, a school caretaker, the Vetting and Barring scheme was set up in 2009 to monitor those wanting to work with children or vulnerable adults. However it has been criticised for being too bureaucratic and too restrictive.
The new system: The measures in the bill will scale back the scope of the work not open to barred individuals.
A merger of the Criminal Records Bureau (CRB) and Independent Safeguarding Authority will provide a more 'streamlined' checking service for about 4.5 million people who work "closely and regularly" with children or vulnerable adults.
The vetting of teachers will continue - but those who do occasional, supervised volunteer work will not need checks.
Job applicants will also be able to see the results of their criminal record check before their prospective employer so mistakes can be corrected.
The bill will provide for the "portability of criminal records checks between jobs to cut down on needless bureaucracy".
It has been welcomed by child protection charity the NSPCC - but the organisation also expressed concern that volunteers in schools and children's homes would be exempt from checks. It also claimed there was a "gap" in the protection of vulnerable 16 and 17-year -olds because people who worked with them in sports clubs and faith groups would not be vetted under the new rules.
The old system: CCTV systems, including Automatic Number Plate Recognition (APNR) cameras, are not subject to any special regulations specific to them or their use. However, the use of personal data captured by CCTV is subject to regulation as is the covert use of CCTV systems by local authorities.
The new system: The government promised to "further regulate CCTV" in the coalition agreement. If this bill becomes law the home secretary will be required to publish a code of conduct on using CCTV and other surveillance cameras.
A new Surveillance Camera Commissioner will be appointed to monitor the operation of the code and must report annually to Parliament.
The old system: The Regulation of Investigatory Powers Act (RIPA) passed in 2000 regulates public bodies, including councils, who can use covert powers of investigation. Some councils have been criticised for using the powers to investigate dog fouling and false claims over school catchment areas.
The new system: Councils will now need to justify their need to use these powers before a magistrates court.
The previous Labour government was also committed to reforming the way councils use RIPA.
- Police stop and search powers will be restricted.
- On Freedom of Information, public bodies will have to proactively release electronic data in re-usable formats and companies who are wholly owned by two or more public bodies will now be subject to FOI requests.
- Schools must get the permission from the parents of children under 18 if they want take their child's fingerprints.
- Those with historical convictions for consensual gay sex can apply to have them disregarded.
- Private landowners will not be allowed to clamp vehicles on their land but they will be able to recover unpaid parking charges from vehicle owners.
- Measures which allow serious fraud trials without a jury will be scrapped.
- The timing restrictions on when marriages and civil partnerships can take place will be abolished.
The coalition agreement promised to "introduce a new 'public reading stage' for bills to give the public an opportunity to comment on proposed legislation online". The Protection of Freedoms Bill will pilot this new system.
Before becoming law, a bill goes through several stages in the both the House of Commons and the House of Lords where MPs and peers have the opportunity to scrutinise it and make changes. For the first time the public will be able to comment on each clause of the bill on a specially created website.
The government will then collect the responses and present them to a cross-party committee of MPs during the bill's passage through the House of Commons.
David Cameron has said that opening up the legislation process in this way "will mean better laws - and more trust in our politics."