Accessing pensions can influence whether you qualify for income related benefits.
If a person (or their partner) takes money from their pension pot before state pension age then the whole pot becomes assessable as either income or capital when determining qualifying entitlement for benefits.
If no money is taken from the pot then it is not assessable until state pension age, when account is taken of it whether accessed or not.
If a pension pot is accessed and spent or given away account could still be taken of it under deprivation rules which can limit benefits if a person has deliberately deprived themselves of means to support themselves
Further detail on this is contained in the Department of Work and Pensions factsheet