Ukrainian refugees without UK family members applying for visas under the new sponsorship scheme have been told not to travel to Britain until they have received a decision on their application.

Ukrainian refugees and their sponsors are now able to fill in an online form on Gov.uk under the Ukraine Sponsorship Scheme, which formally launched on Friday.

Those with valid passports who apply under the scheme will receive a permission letter from UK Visas and Immigration (UKVI) confirming that they can travel to the UK.

Ukrainians without passports will have to submit their biometrics at a visa application centre, where they will receive a visa.

The Government said refugees should not make their own way to the UK before they have received a permission letter or visa.

It said it is prioritising applications under the scheme and aims to make a decision “as quickly as possible”.

Guidance published on Friday says that, by completing the online application form on Gov.uk, both the applicant and sponsor have given permission for their data and contact details to be shared for the purpose of checks.

Those who hold a valid Ukrainian passport will not need to attend an appointment at a visa application centre to give their biometrics.

When they reach the UK, they will receive a six-month entry stamp.

They will need to submit their biometrics within this time to extend their stay for up to three years and to receive a residence permit.

Ukrainian nationals and their immediate family members, who were living in Ukraine before January 1 this year, will be eligible to apply under the sponsorship scheme.

Relatives who fall under this definition are a spouse or civil partner, unmarried cohabiting partner of at least two years, a fiance/e or proposed civil partner, a child under 18, and a parent of a child who is under 18.

Applicants and sponsors will undergo security and safeguarding checks.

Enver Solomon, chief executive of the Refugee Council, said: “The Ukraine sponsorship scheme is a complex visa scheme that will inevitably be inaccessible to the most vulnerable refugees, such as unaccompanied children.

“A humanitarian crisis requires a speedy and compassionate response, not one that puts bureaucratic hurdles ahead of the immediate needs of people whose lives have been ripped apart.

“The Government must waive visas to allow any Ukrainian to reach safety in the UK as a refugee and then match them with Britons who have shown incredible generosity by wanting to welcome Ukrainians into their homes.

“At the same time, we urge the Government to rethink its cruel and harmful proposals in the Nationality and Borders Bill going through Parliament that will criminalise any Ukrainian seeking safety who arrives in the UK without a visa.

“The Government must not discriminate between those refugees it considers to be more deserving of our protection than others. By definition, all those fleeing the brutal conflict in Ukraine are in need of safety.”