Public sector IT outsourcing will grow by £26bn to £100bn by 2013, with services to the citizen alone worth £56bn, according to researcher Kable.

The value of services to government will also rise, from £33bn to £44bn in the next five years, says the Public Sector Outsourcing report published today.

To get the most from the investment requires clarity, said Kable associate director Seyi Agboola.

"The agenda demands increasingly sophisticated programmes through increasingly diverse channels," she said.

"If the private sector is to rise to the challenge, then government has to be explicit about what it expects."