Almost one in 10 councillors in London either work for property businesses or have received gifts or hospitality from them, a Guardian investigation into the depth of links between town halls and the property industry has revealed.

Nearly 100 councillors in the capital work for property companies or lobbying and communications consultancies involved in planning, according to declarations of interest made by elected representatives. Some of them also sit on planning committees making decisions over major developments, including volumes of affordable housing.

In Thursday’s local elections, housing is expected to be the second-biggest issue for voters behind health, according to polling by Lord Ashcroft.

Campaigns in boroughs including Westminster, Kensington and Chelsea and Wandsworth have been dominated by housing issues. In Westminster, where former deputy leader Robert Davis is under investigation for his links to the property sector exposed by the Guardian, Labour has pledged to accept no hospitality from developers or their agents and that all meetings will have a council officer present and will be minuted.

The Guardian found that 43 councillors work for communications consultancies specialising in planning, which are appointed by developers to communicate with local residents, pressure groups and councillors before planning hearings. A total of 48 others either own or work for property companies.

Just over 100 councillors received hospitality from property companies including lunches and dinners at top Mayfair restaurants, tickets to Premier League football matches, seats at Proms concerts and bottles of fine wine. The figures are drawn from members’ latest hospitality registers that date back between one and seven years.

Sir Alistair Graham, the former chairman of the committee on standards in public life, claimed the extent of the overlap between the property industry and councillors “undermines trust” and potentially “the important national objective of increasing affordable housing”.

“These networks have the capacity to help property companies default on their responsibility to build affordable housing,” he said. “We should place restrictions on council members who are also employed by property companies and make it a legal requirement that they must stand down when decisions on planning issues are discussed which they may have an issue in.”

Councillors with dual interests include Andrew Smith, the Conservative chairman of one of Westminster’s planning committees who works for Westbourne Communications – whose services include “delivery of planning approvals” – and Alex Karmel, a Conservative member of the planning committee at Hammersmith and Fulham who works for Thorncliffe, a consultancy that has a button on its website labelled: “Get me planning approval please!”

Taking hospitality and working for outside organisations is permitted by councillors as long as it is declared. Typically, in council codes of conduct, members only need to withdraw from participating in any matter if they have a “disposable pecuniary interest”, which can include employment.

Some of the councils with the highest levels of hospitality or declared interests in property companies are producing levels of affordable housing that fall short of the London mayor’s 35% target in the capital. In Wandsworth, where 17 councillors declared interests or entertainment with property companies, 19% of new homes built between 2013 and 2016 were affordable. In the City of London, where 12 councillors declared interests, only 3% were affordable.

Ravi Govindia, the leader of Wandsworth, strongly denied any link, stating that 1,700 affordable homes will be completed in the next three years and that “to suggest that we are not playing our part in delivering the low-cost housing London needs is complete and utter fallacy”.

Govindia, who is director of a gorilla safari business, was entertained by property companies 11 times in 2016 and the first half of 2017 including at Simpsons in the Strand and the Ned. He said: “It is important that we engage with property companies, housing associations and senior government officials so that they better understand our housing needs and priorities.” Govindia said he was “wholly open and transparent in my dealings”.

Councillors working for planning consultancies have denied any conflict of interest and say they do not lobby on applications in their own boroughs. Smith said: “It would be a breach of the councillor’s code of conduct if there were any conflict of interest between my role as a councillor and my occupation … As a consultant I have never worked to promote planning applications in Westminster.”

Karmel said: “I fully comply with my council’s own code of conduct. It is unacceptable for councillors, of any party, to accept any form of payment to lobby their own council.”

Almost a third of councillors who registered hospitality from property companies only reported one instance of entertainment or gifts. The rest recorded at least two meetings and in many cases several more.

The research comes in the wake of outrage at the conduct of Davis, who stood down after the Guardian revealed he had been entertained by property industry figures 150 times in three years while in his previous role as chairman of the planning committee. The council’s leader, Nickie Aiken, launched an inquiry into the borough’s planning process to reassure residents it is “not only impartial, but is seen to be impartial”.

Davis said any suggestion he did “anything other than to further the interests of the city and its residents are baseless and strenuously denied”. An internal inquiry into Davis is continuing and he is standing again in Westminster.

One of Labour’s candidates is David Boothroyd, who sits on Westminster’s main planning committee and also works for Thorncliffe, which offers “lobbying and committee success” services. Boothroyd said the firm “expressly prohibits any of its employees from any form of engagement, on behalf of a client, of a local authority area of which they are an elected member”.

Other councils received repeated entertainment. Darren Rodwell, the Labour leader of Barking and Dagenham, received free tickets to watch West Ham six times in 2016 and 2017 including from construction company Mullaley and a £3,680 four-day trip to China paid for by Chinese property investor PGC Capital.

Peter John, the leader of Southwark council, recorded 18 occasions of hospitality with property developers and their agents between 2015 and 2017 including Berkeley Homes, which invited him to a party, a ball and a test match at Lords. John did not respond to request for comment.

A spokesman for Rodwell said: “There is no conflict of interest.” The China trip, he said, “was part of the leader’s role as London councils’ city development representative to bring in investment in all 32 London boroughs”.