SERGIY Sokolov couldn't believe it when Russia invaded Ukraine on February 24.

It was his birthday. His mum Svitlana - with whom he had come to the UK in 1999 when he was just 11 - had recently made the decision to return to her native Ukraine to live.

She had packed up her life in London, but put off buying plane tickets until after Sergiy's birthday.

Then the Russians invaded.

"So we didn't celebrate my birthday, and we didn't book tickets," said Sergiy, 34, who is just starting work as an advisor with York Citizens Advice.

He himself had recently moved from London to York with his family - Polish wife Kasia and two children, Yulia, 7, and Mieszko - in search of a more relaxed way of life.

With nowhere in the UK to live, his mum is now staying in York with the family, too.

The Russian invasion shocked Sergiy.

"It was very hard to believe," he said. "It is something I never expected.

"There are such intense links between Ukraine and Russia. Every other Ukrainian person will have relatives or friends from both Russia and Ukraine."

Soon after the war started, Sergiy, a former head chef, began volunteering to help Ukrainian refugees in York.

He operated as a translator and interpreter, helping to arrange support for desperate families.

Now he has been taken on as a paid member of staff at York Citizens Advice, so that he can continue that work on a professional basis.

Working with recently-arrived refugees has been emotional and draining, he says. Very often, the new arrivals are exhausted and traumatised.

"Most of them are women and children," he said. "They have left behind husbands, sons, fathers. Most of them have lost all the men in their family."

He knows of one family of arrivals in which three generations - mother, grandmother and great-grandmother - have all lost the men in their lives.

"It is just unbelievable," he said. "I just try to do what I can."

York Citizens Advice chief executive Fiona McCulloch says he is being modest. "He's absolutely fantastic." she said. "He's got so much energy and enthusiasm. He's going to be a huge asset."

Sergiy is profoundly grateful to the people of Britain for the support they have given to Ukraine - and the way they have welcomed refugees.

"I am very proud to be living in Britain," he said.

Next month, on October 15, he will be involved in the launch of a new York Ukrainian Society, the aim of which will be to provide a network of support for Ukrainian refugees living here.

His own memories of Ukraine are more distant now.

He and his mum lived in a flat in the small central Ukrainian city of Cherkassy.

His memories are mainly happy ones - of family, and relatives.

But he remembers that even back then, there were attempts to suppress aspects of Ukrainian language and culture.

He remembers piles of textbooks in his local school. "They were from the old Soviet Union. They were in Russian, and they had the USSR stamp in them."

Now, he just hopes that, somehow, the war can be brought to an end.

"I want for this to stop, so that people don't lose their lives," he said. "Every single person only has one life. They need to be allowed to live it."