New rules for arriving travellers have been introduced due to fears over the Omicron variant of coronavirus.

Here the PA news agency answers key questions about what is changing.

– What changed at 4am on Tuesday?

Travellers arriving in the UK must now have evidence of a negative result from a Covid-19 test taken in the two days before their departure.

If your journey begins on a Friday, you could take the test any time on the Wednesday, Thursday or Friday.

– What type of test is required?

Lateral flow tests are accepted, which are cheaper and quicker than PCR tests.

– Can I get a test from the NHS?

NHS tests cannot be used for international travel. You must purchase a test from a private company.

– What happens if I do not take a test?

You may not be able to board your transport to the UK.

The Department for Transport said anyone who does arrive in England without evidence of a negative test could be fined £500.

– How about if I test positive?

Your transport provider is highly unlikely to allow you to board if you inform them you have tested positive.

You will be required to follow the rules for positive coronavirus cases in the country you are in, which will probably involve finding accommodation at short notice.

If you travel abroad in the coming days you face spending Christmas overseas if you test positive.

– Are there any overseas destinations I can arrive from without evidence of a negative test?

Only a handful. They are Ireland, the Isle of Man, Jersey, Guernsey, the Falkland Islands, St Helena, Ascension Island and Ethiopia.

The latter is on the list due to the security situation there.

– Do children need to get tested?

The Department for Transport said children aged 11 and under do not have to take a test before travelling to England.

– What if I cannot get tested for medical reasons?

Older people do not need to get tested if they are travelling to the UK for urgent medical treatment – or accompanying someone travelling for treatment – and it is “not reasonably practical” to be tested.

People are also exempt if they have a medical condition which means they cannot take a test, but they must present a note from a medical practitioner when they check in with their transport provider and when they arrive in England.

– Is anyone exempt because of the job they do?

People do not need a pre-departure test when arriving in England if they do a limited range of jobs, such as aircraft pilot or crew, Eurostar worker, international lorry driver or defence personnel.

– What other testing rules have changed due to the Omicron strain?

Even fully vaccinated arrivals must now take a post-arrival PCR test, and self-isolate until they get a negative result.

– What if I am not fully vaccinated?

You must continue to purchase two post-arrival PCR tests, and self-isolate for 10 days.

– How do I get a post-arrival test?

You must order it from a company listed on the Government’s website, but there are long-standing complaints that some firms have misleading prices and poor service.

– What about the red list?

The list was scrapped in October, but later resurrected due to fears over the new Omicron variant.

On Monday, Nigeria became the 11th country to be added. All the countries are in Africa.

– What happens if I arrive from a red list country?

Arrivals from destinations on the list must spend 10 days in a quarantine hotel at a cost of £2,285 for solo travellers.

– Why is the reintroduction of the red list so controversial?

Some UK holidaymakers were already in red list countries when the announcement was made, meaning they have unexpectedly been required to enter a quarantine hotel on their return.

– How has the travel sector responded to the changes?

UK travel bosses are frustrated that new rules have been imposed just weeks after restrictions were eased, and before the impact of Omicron is fully understood.

– What does the Government say?

Health Secretary Sajid Javid said “we are taking decisive action to protect public health” when the latest rule changes were announced.