Almost a third of all 18-year-olds in Britain have applied for undergraduate courses this year, a record high spurred on by aggressive marketing campaigns.

A day after A-level results were published in England, Wales and Northern Ireland, the admissions service Ucas said more students than ever before had obtained places through its clearing process – 17,000 out of the 210,000 UK students who gained places, a 15% rise from the same point in 2018.

Some universities are resorting to unusual tactics to advertise their courses, with the University of Hull finding itself in hot water in Bradford after a guerrilla marketing campaign went wrong.

Residents woke to find slogans advertising “Clearing at Hull, less setback, more comeback,” stencilled in pink, white and black writing across the city, including on a listed building.

“The University of Hull has carried out marketing activities in various cities, of which stencilling is one. Plans were in place to remove all signage by the end of today at our expense. We are working with City of Bradford metropolitan district council and will of course comply with any specific instructions,” the university said.

But the local authority was unimpressed, threatening to fine the university over what it said was graffiti. “Bradford is the youngest city in the UK, which is why it is seen as an attractive recruiting area for other universities and colleges, but this is definitely not the way to go about it,” a council spokesperson told the Telegraph & Argus.

Other universities have been using incentives such as bursaries. The University of Ulster is offering undergraduate applicants from the UK scholarships worth £2,500 a year as part of a package of discounted tuition fees and help with accommodation and travel costs, along with a reduced entry tariff.

The University of Hull tried to catch the eye of potential students in Bradford with a controversial graffiti campaign. Photograph: Alamy Stock Photo

Hull is offering similar incentives, including a £2,000 cash scholarship for students with three Bs at A-level. But such marketing gimmicks are not new: in previous years universities have offered potential students free laptops and tablets, as well as funding.

The increased competition follows changes in 2015 that removed a cap on the number of places that individual universities in England could offer, leading many to expand rapidly and use marketing campaigns to attract and recruit more students.

Those efforts have helped counteract a dip in the number of 18-year-olds in the population. While the total number of British students applying has fallen compared with 2018, the proportion of 18-year-olds applying to university has risen to a record high of 30%.

Universities have redoubled their efforts to recruit more students from disadvantaged areas. Institutions in England and Wales reported a higher proportion of students from low-participation areas accepting places, with the rate in England hitting a record level of 18%. But in better-off areas the participation rate remains much higher, with nearly 42% of 18-year-olds going to university.

Ucas said there had been a sharp rise in the number of students using clearing as their first point of application, with 4,500 bypassing the traditional timetable to seek places by applying after getting their results.

Adrian Dutch, the University of Westminster’s director of global recruitment and admissions, said: “Clearing is now a conscious choice for a lot of students who are behaving in a more tactical and informed way. Ucas tell us more students are going into clearing even though we know there’s fewer students in the marketplace due to the demographic dip. At Westminster we’ve definitely seen a rise in calls on our clearing hotline and in the number of offers we’ve made.”

The University of Cambridge said a pilot scheme allowing students who had been turned down during its main applications round to reapply had been a success after 67 students from disadvantaged backgrounds gained places.

“It is wonderful to see that so many who may not have managed to show their full academic potential during the main admissions round have gone on to excel at A-level due to their hard work and determination,” said Sam Lucy, Cambridge’s director of admissions.

Seventeen of the students will study medicine while others will study economics, engineering, law and natural sciences.

A survey by PA Media on Friday found that places on more than 25,000 courses at 146 UK higher education institutions were on offer through clearing, including courses at several universities that are members of the Russell Group of leading research institutions.

The shortage of local applicants has led universities to recruit more EU and international students. Ucas said the number of undergraduates coming from EU countries was similar to last year, at 27,000, but there was an increase in non-EU students, up 6% to more than 34,000, a third of whom are from China.