Sir Lindsay Hoyle, the Commons deputy speaker running to replace his boss John Bercow, said the two issues needed to be addressed as he pitched for the top job.
Asked if there was an alcohol problem in parliament at a hustings with journalists, the Labour MP for Chorley since 1997 revealed: “I do think there is a drink problem.
“I think it needs to be addressed and the support needs to be given, that’s why health and wellbeing has got to be extended.”
He added: “It’s not just drink we’ve got to catch out, there is a drug problem.
“I genuinely believe that counselling and real support should be available for all staff and members.”
When quizzed on his comments, Sir Lindsay appeared to row back, saying: “I believe there will be a drug problem – there is a drug problem right across this country.
“I don’t believe that somebody who walks in here may not be tempted into drugs.
“What I’m saying is that we should have health and wellbeing in place for drink and drug counselling and real support for anybody.”
There are eight other candidates vying over the next month to become the next Commons speaker.
They are fellow deputy speakers Dame Eleanor Laing and Dame Rosie Winterton, the longest serving female MP Harriet Harman, Labour MPs Chris Bryant and Meg Hillier, and Conservative MPs Sir Henry Bellingham, Shailesh Vara and Sir Edward Leigh.
The winner will take replace Mr Bercow and be in charge of keeping order in parliament’s lower house and holding powers, including sometimes selecting what gets voted on.
Sir Henry disagreed with Sir Lindsay’s assessment of MPs’ relationship with alcohol.
“I don’t believe there is a drink problem as such,” he said.
“People just need to show judgement, they need to be mature, and honestly some of my colleagues just need to grow up.”
Dame Rosie added: “Does Parliament have a greater drink problem than the world outside? I’m not sure.”
A parliamentary spokesperson said it takes substance misuses “very seriously” and “should drug use be identified in parliament, appropriate action would be taken”.
They added there have been a “number of actions to promote responsible alcohol consumption among all customers on the estate”.