Planners in Aberdeenshire have backed Donald Trump’s controversial plans to build up to 550 luxury homes near his golf course, despite a record number of objections.

The council’s planning officers said the scheme, due to be built in phases at a cost of around £25m, had “considerable merit” for the local economy and recommended that it is approved by the council next month, subject to conditions.

But the US president’s opponents furiously accused planners of overlooking more than 20,000 objections, including those from the local community council, transport officials and 18,722 people who signed a petition organised by the online platform 38 Degrees.

Cllr Martin Ford, Trump’s most prominent critic on the council, said the proposals ignored the promises made in 2008 when Trump first won permission to build a £750m golfing and holiday resort on the site, overriding legal protections for its rare coastal dunes.

Ford said the 2008 masterplan was being used as a Trojan horse to allow Trump to build a profitable housing estate, without any of the the extra jobs, amenities and investment he promised. The housing plans also breached a series of conditions in the local development plan, he said.

He said this reinforced strong suspicions that Trump was getting preferential treatment, and urged councillors to vote against the proposals. Trump’s son Eric visited Scotland last week, a few days before planning officers published their report.

“The Trump Organization wants the housing without building the resort development it was supposed to fund. That would be hugely financially beneficial to Mr Trump, but it is surely not in the public interest and risks creating a precedent other developers might wish to follow,” Ford said.

Planning officials have warned the Trump Organization it still needed to meet a series of extra conditions before they finally approved his application. Those include better flood protection, improved access for non-motorists, redesigned streets, improved tree protection and an agreement to pay up to £5m towards affordable housing in the area.

The Trump Organization has been approached for a comment.

The council has given Trump a rare dispensation to sidestep rules that require a quarter of the homes in new housing developments to be affordable to help address its significant homelessness problems. The council had 6,000 people on its waiting list last year.

It has instead allowed Trump Golf Scotland, the business that runs the golf course, to pay a 25% surcharge towards affordable homes elsewhere in Aberdeenshire because so far it has refused to include cheaper or rented homes in its plans.

The council’s rules stipulate this deal can only be allowed in “rare and exceptional” cases, and only as a last resort.

The company will have to pay an initial £770,000 surcharge for the first phase of 82 homes and community facilities. Trump would then have to pay another £4.2m for the remainder of the project, unless it included affordable housing in future phases.

Apart from some two-bedroom cottages and flats for resort staff, the housing estate will be made up of three, four and five-bedroom town houses and detached homes, each with separate garages. There will also shops, extra bedrooms for the small boutique hotel in the estate’s Victorian villa, communal gyms and a “town hall” community centre.

But the planning department report reveals that Aberdeenshire’s transport department has recommended the development is rejected, because it breaches the council’s sustainable travel plans and has “insurmountable accessibility issues”.

Transport officials said there was insufficient space for safe walking for children going to local schools; it was too far from bus stops; it put too much emphasis on private car use and had limited scope for safe cycling access to nearby roads.

In a further development, the Scottish Environment Protection Agency has given the Trump Organization approval to continue running its golf course, clubhouse and restaurant without building a proper sewer connected to the area’s sewer system.

Sepa has allowed it to continue using a so-called “soakaway” which allows waste and sewerage to drain away on site – which was installed in 2012 and was supposed to be replaced by a permanent sewer by the end of 2018 – for the foreseeable future.