The chief executive of Birmingham City Council has defended the amount of money the local authority spends on consultants, insisting that he and his senior colleagues are too busy trying to run “inefficient systems” to carry out additional work.

Stephen Hughes said a “trail-blazing” business transformation programme would deliver first class IT systems and usher in a culture change by eradicating outdated working practices among staff, but it could not be achieved without private sector experts.

He was responding to a critical scrutiny inquiry which found that the council has no idea how much it spend on consultants.

The bill is believed to have hit at least £120 million for 160 temporary appointments over the past two years, but poor computer systems and the absence of centralised record keeping mean that accurate records do not exist.

Mr Hughes told the council’s main scrutiny committee yesterday that he regretted failing to stir up enthusiasm for business transformation, which seeks to identify £1 billion of savings over a 10-year period.

Crucially, the project will also deliver major changes in working practices among the council’s 40,000 non-teaching staff, wiping away departmental boundaries and requiring employees to be far more flexible.

He added: “We are regarded as a trail-blazer. We have had cabinet members here, government departments and foreign governments looking at what we are doing in Birmingham. That really hasn’t hit the headlines in the way it should do.

“Business transformation is not just about making savings, it is also about releasing resources to enable us to improve services.

“Once all of these programmes have been delivered we really will be at the cutting edge of councils in this country.”

He promised to “berate” senior officers urging them to get rid of a silo mentality which was holding back progress.