International leisure travel is still banned from the UK – and the prime minister has said he cannot guarantee that overseas holidays will open up from 17 May, as originally mooted.The government says it hopes people will be able to travel to and from the UK to take a summer holiday this year, “but it is still too soon to know what is possible”.Ministers advise people “not to book summer holidays abroad until the picture is clearer”.With just six weeks remaining before the hoped-for resumption of foreign travel, this has come as a shock.But the government has confirmed that a “traffic light” system will be used to indicate risk and consequent arrival protocols. Read moreAs travellers, airlines and holiday companies take in the lack of certainty, these are the key questions and answers.What has Boris Johnson said?The prime minister said the government wants to see a return to non-essential international travel as soon as possible, while still managing the risk from imported cases and variants of concern.The expectation was that cautious opening up would begin as planned on 17 May, as originally mooted.Sign up for the latest deals and insider tipsBut the Roadmap Reviews: Update document says: “We are not yet in a position to confirm that non-essential international travel can resume” on that date.What is the government waiting for?More information on “the latest situation with variants and the evidence about the efficacy of vaccines against them”, according to the document.The government “will confirm in advance whether non-essential international travel can resume on 17 May, or whether we will need to wait longer before lifting the outbound travel restriction”.The trouble is: even with six weeks’ warning, the travel industry would struggle to deploy appropriate capacity. Airlines and holiday companies normally plan capacity months and years ahead, not days and weeks.Understandably the government wants to make its decision as late as possible, so as to minimise the chance that the outlook in a country could change significantly, and it has been suggested the final decision could be made as late as 10 May – just a week before the first possible date for international travel.Having to work with a very late decision would leave the firms in an almost impossible situation after over a year of heavy losses.Do they make educated guesses and put plenty of capacity into, say, Portugal, but run the risk of a late change? Or do they cancel everything for May and possibly into early June, and start planning only when the initial classification is known?If travel firms cannot be reasonably certain of operating at a profit, cancellation of existing bookings, at least for early summer, looks the most likely.I have a holiday booked from 17 May onwards. What are my rights?At present all you can do is assume that the trip will be going ahead as planned. While travel firms assess their options, the contract you have will still be in force. For you to cancel the trip now would be overly hasty – you would certainly be charged a hefty cancellation fee. Only if and when the company announces a cancellation itself are you entitled to a full refund. Holiday firms are likely to start announcing some cancellations soon, though initially only for late May.How will the traffic light system work?Boris Johnson said travellers returning to England, as well as incoming overseas citizens, will have to comply with a system in which each nation (or possibly individual regions) is classed as red, amber or green. All three categories have stringent conditions attached.The green category – currently occupied only by Ireland – is likely to be expanded. There will be no need to quarantine on return to the UK, but pre-departure and post-arrival tests will still be needed.“This new category will accommodate countries where we judge the risk to be lower, based for instance on vaccinations, infection rates, the prevalence of variants of concern, and their genomic sequencing capacity (or access to genomic sequencing),” says the government.The assumption at present is that the current red list – with 11 nights of mandatory hotel quarantine at a cost for a single traveller of £1,750 – will continue.The vast majority of countries are in, and will remain in, the amber category. This requires 10 days of self-isolation at home, with (in England) the option to take an extra test after five days and leave quarantine.In time, people who have completed a course of vaccination may be able to avoid the need to quarantine on return from “amber” nations. When can I get a ‘vaccine passport’ for going on holiday?You can’t yet, but may be able to by the summer. The government says: “The NHS is working on providing individuals with the means to demonstrate their Covid status through a digital and non-digital route, and is working with experts to put security and privacy at the core of this approach.“When non-essential international travel does resume, the NHS solution will facilitate international travel where certification is required, and we will look to establish arrangements with other countries and international organisations to establish mutual recognition of certificates.”When will we find out more?It is unclear, but the government says: “The Global Travel Taskforce will publish its report, setting out more details on this system, later this week.”