From Longman Dictionary of Contemporary Englishgive somebody a blank chequegive somebody a blank chequeBritish English, give somebody a blank check American EnglishLET/ALLOW to give someone permission to do whatever they think is necessary in a particular situation → blank cheque
Examples from the Corpus
give somebody a blank cheque• We cannot let our democracy become a matter of simply giving a bunch of politicians a blank cheque to govern us every five years. 