in bed with

in bed with - (AmE) - в сговоре с; заодно с
Carriers' performance isn't stringently controlled because they are in bed with regulatory bodies. - Деятельность компаний-перевозчиков контролируется слабо, так как они в сговоре с органами контроля.

see also [in cahoots with]
[одним миром мазаны]
[hand in glove]
[you scratch my back, i'll scratch yours]