LONDON (Reuters) - A lawmaker from British Prime Minister Theresa May’s minority ruling Conservative Party deliberately made false declarations over his spending in a 2015 election, a prosecutor told a London court on Tuesday.

FILE PHOTO: MP Craig Mackinlay speaks in favour of leaving the EU at a Brexit debate called "The Morning After the Vote", hosted by Thomson Reuters at Clifford Chance, in London, Britain, April 25, 2016. REUTERS/Peter Nicholls

Craig Mackinlay, 52, who beat leading Brexit figure Nigel Farage in the parliamentary election for South Thanet in southeastern England in 2015, earlier this year pleaded not guilty to the charges.

“Far from being complete and inaccurate, the (expenses) returns were woefully incomplete and woefully inaccurate, and deliberately so,” Prosecutor Aftab Jafferjee said in his opening of the case.

Mackinlay appeared at Southwark Crown Court alongside his election agent Nathan Gray and Marion Little, a campaign director from Conservative head office, who both also deny charges over the expense returns.

Jafferjee said the three shared responsibility for the submission of inaccurate election expenses returns, and that Mackinlay was not an innocent bystander in what unfolded.

Certain “notional” spending was omitted from expense returns when it should have been included, he said, such as the salaries of Gray and Little, which were paid for by Conservative headquarters in London.

Little’s defence, that she was working on the national campaign to defeat Farage’s UK Independence Party (UKIP), didn’t fit with the central role she played in Mackinlay’s operation, Jafferjee said, adding that the importance of beating Farage meant it “was clear that this was not going to be any ordinary election campaign.”

“The primary objective was clearly to get Craig Mackinlay elected and defeat Nigel Farage,” Jafferjee said.

“She was there for one purpose: vote Craig Mackinlay, not vote Conservative generally. Craig Mackinlay knew that.”

The 2015 general election saw Mackinlay beat Farage, the former head of UKIP, into second place by 2,812 votes.

He then retained the seat in June 2017 with an increased majority of more than 6,000 votes as support for UKIP collapsed with Farage - who played a key role in securing Britain’s vote to leave the European Union in 2016 - no longer the party’s candidate.

In May 2017, prosecutors ruled out bringing more widespread criminal charges over allegations of expenses fraud by the Conservatives during the 2015 campaign.

However the Electoral Commission, the independent election watchdog, last year fined the Conservatives a record 70,000 pounds ($92,500) for breaking rules by incorrectly reporting its spending.

May’s Conservatives remain in power only through an agreement with 10 Northern Ireland MPs after losing their majority in the 2017 general election. If Mackinlay were to be found guilty, he could be jailed for up to a year and there would likely be pressure for a by-election to replace him.

The case is expected to last several weeks.