The number of asylum applications in Britain in the year to June was up 19% on the previous 12 months and at its highest in two decades, the government said on Thursday.
The Home Office, or interior ministry, said 78,768 asylum applications were made by people who arrived in the country illegally.
Prime Minister Rishi Sunak has made cracking down on illegal migration a priority before a national election expected next year, pitching his Conservatives as being tougher on the issue than the opposition Labour Party, which enjoys a strong lead in opinion polls.
Seeking to deter people from arriving in Britain, it is moving migrants onto disused military sites and barges and intends to send asylum seekers to Rwanda, although that plan has been bogged down in the courts.
The government said in the year to June there were 23,702 initial decisions made on asylum applications, up 61% on the previous year. Of those, 71% were grants of refugee status, humanitarian protection or alternative forms of leave.