Builders, gardeners, window cleaners, painters, decorators and domestic cleaners have been instructed to stop working immediately.
Plumbers, electricians, carpenters, roofers and scaffolders can only carry out emergency work on homes; and car, motorbike and bicycle mechanics can only take custom from key workers.
It comes as the number of confirmed cases of Covid-19 in the Bailiwick rose to 45 last night, and three people with positive diagnoses were being treated at the Princess Elizabeth Hospital.
Those three in-patients were not in intensive care and did not need ventilators.
In Jersey yesterday, a second coronavirus-related death was announced, the person was in their 70s and described as having significant underlying health conditions.
As part of Guernsey’s tougher lockdown measures, restaurants, cafes and kiosks, which had reinvented themselves to deliver takeaways, must now shut, although the Meals on Wheels service is exempt from this.
It means Guernsey’s measures are now significantly stricter than those in the UK, and reflects the island’s status with a single hospital and limited healthcare resources that could become overwhelmed.
Jersey has also now entered a lockdown period, but its measures are not as comprehensive as Guernsey’s.
There had been confusion over the Guernsey States’ messages of ‘stay at home’ but also ‘go to work’, and a number of grey areas had emerged with particular queries over construction workers, gardeners and window cleaners.
The Civil Contingencies Authority has clarified the situation and published 11 pages of guidance which are on the gov.gg website.
Deputy Gavin St Pier, the chairman of the authority, said the more stringent measures would help prevent unnecessary deaths.
He apologised for the initial confusion, but explained that the lockdown decision had to be taken quickly and they had since been able to toughen up the rules and add more detail.
‘We know our original guidance issued on Friday evening was not clear enough, and not strict enough in limiting those workplaces which should be allowed to open.
‘We have quickly reviewed the position, which has led to the new guidance we are releasing now.’
The list of essential, permitted retail businesses has been reduced, but still includes supermarkets, pharmacies, petrol stations, pet shops and banks.
Horticultural workers have now been removed from the list of key workers.
The list of jobs regarded as ‘key’ includes some of the island’s lowest paid employees, such as bus drivers, nurses, care home workers, workplace cleaners, supermarket staff and delivery drivers.
These people are crucial for keeping the island going.
Non-retail businesses are allowed to continue trading, but only if they adhere to strict conditions.
Ideally employees should work from home, but if that is not possible then a maximum of two people are allowed on the premises at any one time, and they must be spaced at least two metres apart.
The guidance for individuals remains unchanged – stay at home.
Islanders should only leave their homes for one of four reasons – going to essential work, shopping for basic supplies or medical appointments, acts of kindness for vulnerable people and to exercise.
Deputy St Pier also acknowledged the impact on businesses of the coronavirus crisis, and highlighted further support measures unveiled last week with an ongoing assessment as to whether further initiatives were needed across the economy.
‘I should add, in respect of the payroll co-sharing and grants schemes for businesses and the self-employed, we expect to be in a position to begin making payments in the second half of this week. We recognise this is urgent.’
He also said: ‘I hope that we will within days be able to publicise details of the loan guarantee scheme developed with the clearing banks.’
Director of public health Dr Nicola Brink said everyone had the chance to save lives.
‘While food retailers are open so you can get essential supplies, you should limit your shopping trips to as few as you can, don’t pop to the shop every day for a few extra bits.
‘Our response to this virus, as an island, depends on each of us taking extreme care and making sensible, health-focused choices.’