Braun, an MEP who leads the Confederation of the Polish Crown (KKP), has been charged with publicly denying Nazi crimes at Auschwitz.
On Friday, prosecutors asked the European Parliament (EP) to lift his immunity for the fifth time.
In an interview with private broadcaster Polsat News on Thursday, Nawrocki said he was "president of all Poles," including those who vote for Braun.
He added that polls suggest they make up about 10 percent of citizens.
The president stressed that he disagreed "radically" wit Braun on many issues, particularly historical ones.
Earlier this week, Nawrocki told the daily Rzeczpospolita that he hoped the right would unite in the Senate and did not rule out the KKP joining such an alliance.
Also, the news website Onet reported that the president’s circle was negotiating a joint right-wing Senate list with Braun’s allies.
A KKP associate told the outlet the talks would mark the end of the "sanitary cordon" around the far-right politician.
Sikorski, speaking to the newspaper Gazeta Wyborcza, called the idea "outrageous."
He accused the president of wanting to use the authority of his office to "whitewash anti-Ukrainian, anti-Western, pro-Russian antisemites."
He said Nawrocki was ideologically closer to them than to moderate right-wing parties in the European People’s Party (EPP).
The immunity request
The new immunity request, sent by Justice Minister and Prosecutor General Waldemar Żurek to European Parliament President Roberta Metsola, concerns remarks Braun made in a livestream on 25 August, after he was questioned by prosecutors in Kraków.
Authorities say his comments denied that people were murdered in the gas chambers at Auschwitz-Birkenau.
The offence carries a sentence of up to three years in prison.
"Immunity is not there to protect Auschwitz liars," Żurek wrote on X.
Braun was charged that day over earlier radio and podcast remarks.
He pleaded not guilty but did not dispute having made the comments.
Prosecutors need the European Parliament’s consent to charge him.
The EP has previously voted to waive Braun's immunity in several cases, including over remarks about Auschwitz.
Braun is also on trial in Warsaw over extinguishing Hanukkah candles in the Sejm, Poland’s lower house of parliament, in December 2023.
(ał)
Source: PAP, onet.pl