Former New York Mayor Rudy Giuliani will take time off as President Donald Trump’s media-friendly lawyer to campaign for Republican Rep. Dan Donovan in his heated primary race against disgraced former Rep. Michael G. Grimm.

Giuliani is slated to appear at a Donovan campaign rally Saturday afternoon. The former mayor will also be the keynote speaker at a campaign fundraiser for Donovan that morning, according to local media reports.

Giuliani first threw his endorsement to Donovan in mid-May, saying he would “take a break” from his responsibilities as Trump’s lawyer to help re-elect the incumbent. Trump hired Giuliani in April to represent him in the ongoing federal probe into Russian election interference.

Donovan, the incumbent New York Republican in the Staten Island-based 11th District, is struggling to fend off Grimm, the district’s former representative, who resigned in January 2015 and spent seven months in prison after pleading guilty to tax fraud.

Donovan won the seat in the special election to replace Grimm and won re-election in 2016.

Some observers saw little chance for Grimm when rumors first swirled that he was looking to take back his old seat.

But a poll last week gave Grimm a 10-point lead over Donovan among likely voters in the June 26 primary, even after Trump tweeted his support for Donovan last month.

Trump said Donovan had his “full endorsement” in part because, “Very importantly, @RepDanDonovan will win for the Republicans in November…and his opponent will not.”

Trump also said Donovan “is strong on Borders & Crime, loves our Military & our Vets,” and “voted for Tax Cuts” — although Donovan actually voted against the Republican tax overhaul the president cited.

The mud-slinging New York primary race has seen both candidates fight for high ground as the strongest supporter of the president. Grimm has accused Donovan of voting against Trump “every time it’s mattered,” while Donovan’s campaign has aggressively touted Trump’s endorsement.

The two on Monday clashed in a debate in which Grimm charged Donovan tried to arrange a pardon for Grimm from Trump to keep him from running against the incumbent.

Meanwhile, the Donovan camp has tried to make an issue of Grimm’s ethics issues. A spokesperson for Donovan responded to barbs over campaign financing with a reference to Grimm’s “long line of shady campaign finance dealings” and said the challenger “doesn’t like to pay his bills or taxes.”

The seat is a target for Democrats, who are aiming to win control of the House this November. Trump carried the district by 10 points in 2016, and Inside Elections with Nathan L. Gonzales rates the race Likely Republican.