Plans to build at least 50,000 new houses in Birmingham by 2026 have exposed deep divisions in the city council’s Conservative group.

Council leader Mike Whitby is firmly behind a plan to “grow the population” by 100,000 in order to kick-start the economy.

But a number of his colleagues fear growth on such a scale will mean cramming new homes into inappropriate sites and damaging quality of life.

Councillor Deirdre Alden, who is leading the attack, told Coun Whitby to his face that his proposal was over-ambitious.

Addressing the council leader at a scrutiny committee, Coun Alden (Con Edgbaston) said: “Why do we remain committed to building so many houses? I don’t think we should be.”

She pointed out that the government is moving to ban back-garden development, preventing builders from throwing up houses and flats in the large gardens of detached properties in Edgbaston, Moseley, Sutton Coldfield and other Birmingham suburbs.

Local Government Secretary Eric Pickles has dropped plans to force Birmingham to meet the 50,000 target.

Coun Alden added: “I absolutely agree with this, but I don’t see any way you can have so many houses by 2026 if you don’t go into back gardens.

“You have to be concerned about the quality of life of people who already live here. They don’t want every bit of green belt built on.”

Coun John Alden (Con Harborne) said: “I am concerned about population growth. We have to make sure we build quality houses, not quantity.”

The concerns were rejected by Coun Whitby (Con Harborne), who insisted enough land could be identified for “sensible” development.

He added: “The council owns over 40 per cent of land in Birmingham. We will have to look at smarter use of our land.

“There are areas in the city centre that attract a younger type of person where you can have a higher level of housing density.

“It’s all a matter of balance, but we do need to grow our population to generate wealth.”