Emergency legislation is being brought in after a landmark UK Supreme Court ruling that Scots police can no longer question suspects without allowing access to a lawyer.
Here are answers to some of the main questions on what the decision means for Scottish law.
Q: What has been decided?
The UK Supreme Court has made a ruling that Scottish police can no longer question suspects without their lawyer.
The decision was made after judges in London upheld an appeal by teenager Peter Cadder, whose assault conviction was based on evidence gained before he spoke to his lawyer. His lawyers argued this was a breach of his human rights.
In 2009, he was convicted at Glasgow Sheriff Court of two assaults and a breach of the peace following an incident in the city in May 2007.
Even though the High Court is the highest court of criminal appeal in Scotland, it was overruled by the Supreme Court on a constitutional issue, because the need to consider European human rights legislation was written into the Scotland Act - the piece of Westminster legislation which established devolution.
Q: What does this mean for Scots law?
Until now, suspects could be questioned for six hours without a lawyer present, but judges ruled this violated human rights to a fair trial.
They ruled it contravened a decision by the European Court of Human Rights in 2008 that suspects having access to a lawyer was fundamental to them receiving a fair trial.
The judgement goes against a unanimous decision last October by seven judges at the Scottish Appeal Court.
Almost immediately after Tuesday's decision, ministers announced plans to change Scots law with emergency legislation.
Q: How many cases does it affect? Could there be a flood of appeals?
Ministers say there are 3,471 cases which may relate to the Cadder ruling, although it is up to the Crown to decide whether they are relevant - as Scottish Justice Secretary Kenny MacAskill put it, they are not "sure-fire winners".
The ruling is not retrospective, but it does apply to live appeals and cases which are pending and on-going.
Q: What form will the emergency legislation take?
Essentially, ministers need to make Scots law comply with European legislation, and emergency legislation brought forward by Scottish Justice Secretary Kenny MacAskill will comprise a number of strands.
Firstly, ministers will seek to enshrine in statute, the right of access to a lawyer for anyone who is detained.
The period of detention without charge will also rise from six hours to 12 hours - with the potential to increase that to 24 hours on "cause shown" by a senior officer.
This is a practical measure to ensure that if, for example, a lawyer has to travel from Inverness to Skye to deal with a detained person, they have time to get there.
Lawyers representing multiple accused also need time to interview them individually.
There will also be a special duty placed on the Scottish Criminal Cases Review Commission, which investigates possible miscarriages of justice, so it considers the status of any cases on the basis of whether they have been "finally determined".
Ministers also have to make changes to the legal aid system.
And they will seek to set an appeal limit of 21 days on relation to bills of advocation or suspension - but Mr MacAskill says this applies only to a limited number of summary cases and has given assurances that it will not result in a flood of appeals on many cases.
Q: When will the emergency legislation be passed?
Ministers will bring forward the emergency legislation to the Scottish Parliament on Wednesday.
They have been in discussion with opposition parties to ensure it can be passed and arrangements made to clear parliamentary business so it can happen.
The normal three stages of scrutiny for Holyrood legislation will be taken in one day, and it is hoped the legislation will become law on Friday, by gaining Royal Assent more quickly than normal.
Q: Does this situation result in any increased costs?
Yes. Kenny MacAskill - who spent 20 years as a legal aid lawyer in his past life - put extra costs at between £1m-£4m.
He warned the legal aid budget was "finite", but added: "We cannot expect lawyers to go out to police stations and not get paid."
Q: Will it affect any other areas of Scots law?
In Scotland, no inference can be drawn from an accused exercising their right to silence. But that is not the case south of the Border and Kenny MacAskill is concerned this may now change.
He says there are also implications for the rule of "corroboration", under which two sources of evidence are required to support each fact in a prosecution, which is seen as a mainstay of Scots law.
The senior Scottish Judge Lord Carloway has been asked to look into these and other issues and will report to the government within months.
However, it is not thought any changes in these areas would be made until after next May's Scottish election.
Q: What have Scottish prosecutors said about the decision?
The decision has overturned what has been the position in Scotland for decades.
Despite not knowing the nature of today's ruling, the Crown has seen this coming since last year and has, for example, not relied on comments made during interviews not attended by lawyers unless absolutely necessary.
Q: What about the Cadder case itself?
This is one for the High Court in Scotland, as the the case has been referred back from the Supreme Court.