The proportion of state school pupils admitted to Cambridge is now 59%
The head of Cambridge University has criticised the government over pressure on elite institutions to take more students from disadvantaged homes.
Vice-chancellor Alison Richard said universities were there to educate and lead research and not act as "engines for promoting social justice".
Top universities are under pressure to admit more state school pupils.
Professor Richard also told the Universities UK conference that British institutions were underfunded.
The former Yale professor said universities faced losing their "competitive advantage" to overseas rivals who received more support from their governments.
"The quality of what we provide and our capacity to attract talent are both at risk," she told the conference, being hosted by Cambridge University.
Ministers have increasingly encouraged universities to accept more students from poor families and state schools.
Academics have also been urged to work with private bodies to tailor courses to suit the needs of industry and commerce.
But Prof Richard said: "As institutions charged with education, research and training, our purpose is not to be construed as that of handmaidens of industry, implementors of the skills agenda, or indeed engines for promoting social justice," she said.
Figures released last week showed the proportion of state school pupils offered places at Cambridge University has risen by 4%.
This year, 59% of admissions were from state schools or colleges - the highest proportion of maintained sector admissions since 1981.
And Prof Richard said "neither family poverty, nor misplaced ideas about not fitting in" should discourage students from applying to any university.
But she added: "The question of who we educate should not be driven by budgetary pressures on our institutions."
She acknowledged that "welcome steps" had been taken by Labour to counter underinvestment over the last decade but said they were "not enough".
"The UK still lags, and tough economic times are no reason to abandon our historic strengths by backing away from further investment," she said.
Speaking at the opening of 30 new schools across the country, Schools Secretary Ed Balls called for wider participation in higher education.
"Children of all backgrounds need to be familiar with university, not fear it.
"They need to feel university is for them, so that we ensure they achieve their potential and use their talent," he said.