Business ministers, reciting the creed of open markets, have a terrible habit of refusing to intervene in takeovers. When forced by political pressure to obtain reassurances about national security, headquarters and jobs stipulations, these are often drawn up in a hurry and are riddled with holes. This was the case when Melrose bought GKN and undertakings could easily be subverted. The break-up of Cobham by asset strippers Advent and sale of militarily sensitive flight refuelling technology to a US competitor is another case in point. Taking an 'active interest': Business Secretary Kwasi Kwarteng is keeping an eye on the Ultra deal