Legislation to drive English devolution should be framed to prevent mandarins and ministers from seizing back powers they risk losing, senior peers warned yesterday.

Addressing the House of Lords during the committee reading stage of the Cities and Local Government Devolution Bill, government growth guru Lord Heseltine spoke against the need for ministers to set out a devolution strategy - advising it would either be so general as to be meaningless or so prescriptive as to block the very policy.