Building a relationship with a small group of politicians is the most effective way to influence policy, according to new research by sector think tank nfpSynergy.
The poll asked 160 MPs to choose two from a range of nine possible options for how they would spend a limited lobbying budget if they worked for a charity.
Fifty-five per cent chose "building a relationship with 10 key MPs" as one of their options. Forty-five per cent recommended encouraging the public to lobby their local MPs.
Thirty-six per cent suggested building relationships with relevant select committees or all-party parliamentary groups.
Fewer MPs thought traditional marketing and publicity techniques were effective, with 12 per cent suggesting releasing news bulletins, 11 per cent holding Westminster receptions and 3 per cent hiring public affairs agencies.
Gemma Tracey, a researcher for nfpSynergy, said the study recommended a targeted and local approach to lobbying.
"Cost-effective charities should always endeavour to avoid unselective scattergun tactics," she said.