Lionel Shriver

For the left-leaning, political identity is liable to be closely intertwined with personal identity. The left is collusive, if not presumptuous: should you get on well with leftists at a party, they will blithely assume that you share the same views on the invasion of Iraq, even if all you've talked about is the canapes.

American Journalist

Use 'collusive' when describing covert plans, often illegal.

Secret Schemes

'Collusive' involves partnerships that are deceitful and suspect.

Dishonest Alliances

It's especially relevant when implying secret deals against common rules or laws.