Would-be hosts have compiled a spreadsheet detailing how many refugees have been waiting to come to the UK since the sponsorship programme began on March 18.
The list shows that visa applications for at least 622 Ukrainians, sponsored by 310 UK hosts, are still outstanding, though they were made during the first week of the programme.
A further 261 refugees, sponsored by 130 Britons, are waiting for a decision on applications made during the second week.
Organisers believe the data is not exhaustive and likely underestimates the true number of people who have been waiting since March.
Louise Marcinkevice, who helped compile the spreadsheet and is sponsoring a mother and daughter currently in Poland, said the delays are “incredibly frustrating”.
“We are still waiting for two outstanding applications; we applied within the very first hour.
“Something must have happened. It doesn’t make logical sense to me.”
The chaotic bureaucracy faced by Ukrainians seeking refuge in Britain has been a major issue since the programme was launched.
At the weekend, The Guardian highlighted a series of incidents that have occurred over the course of the brief programme.
In March, Olga Kolisnyk applied to take her two children, aged 11 and six months, to the UK from war-torn Kharkiv.
After first being told her infant would be allowed to travel under her Ukrainian passport, officials later said her baby would have to undergo biometric scans in the Polish capital of Warsaw before she could fly to Britain.
The Homes for Ukraine programme, through which the Kolisnyks applied to come to Britain, was branded “heartless and inhumane” by Briton Angela Le Roux, who is sponsoring the Ukrainian family.
Ms Le Roux said she had been reduced to tears after “rude” government officials refused to clarify the matter and suggested the Kolisnyks seek refuge in a country with better weather than Britain.
Ms Kolisnyk called the uncertain situation “very, very stressful” and called on the UK to make the process “more easy, especially if people want to travel with small children like my daughter".
Other incidents faced by Ukrainians attempting to come to the UK have included a child’s passport expiring before he received his visa which required him to begin his application process again and more than a dozen people not knowing whether their applications had been processed as they waited in increasingly perilous conditions.
Refugees, sponsors and even Home Office employees drafted in to work on the Homes for Ukraine project have complained of confusion and of the programme's slow pace.
As of April 18, only 6,600 Ukrainians had arrived in Britain in the five weeks since the Homes for Ukraine sponsorship initiative launched. A further 15,000 Ukrainians have arrived in Britain under a separate Ukraine Family Scheme which allows applicants to join family members in the UK.
Out of the 65,900 applications received under the sponsorship move, 39,300 visas had been issued as of April 20, Home Office data show.
More than five million refugees have fled Ukraine since Russia invaded the country in February. About three million people have settled in neighbouring Poland, with the remainder spread across Romania, Hungary, Moldova and Germany.
Amid mounting dismay over the slowness of the UK government’s response to the refugee crisis, the Home Office said it has been stepping up visa processing. It also said that some applicants are choosing to stay in neighbouring countries so they can return to Ukraine more quickly.
A government spokesman said: “Thanks to the generosity of the public who have offered their homes to Ukrainians fleeing the war and through the Ukraine family scheme, more than 71,800 visas have been granted, with 21,600 Ukrainians arriving safely in the UK.
“The Home Office are now processing thousands of visas a day — this shows the changes made to streamline the service are working and we’ll continue to build on this success so we can speed up the process even further.”
But UK charities have said the bureaucracy is hurting Ukrainians. Earlier this month, the head of the British Red Cross criticised the “long, complex” application process for Ukrainian refugees and called for the removal of visa requirements altogether, as the European Union has done.
The Refugee Council said the bureaucracy is causing Ukrainians “great distress” and that “paperwork is being put before people".
“Britain could and should be welcoming refugees at a scale and pace not seen before. The public seem to be ready to do this. But the biggest failing at present is the barrier created by the visa programme,” said Enver Solomon, chief executive of the Refugee Council.
“Paperwork is being put before people. Control above compassion. And bureaucracy ahead of agility.”
The charity’s chief said Britons too were “angry and anguished” over the delays and bureaucracy standing in the way of them helping and welcoming Ukrainians.