Larry Page, cofounder of Google and CEO of Alphabet. REUTERS/Steve Marcus Apple, Facebook, Microsoft, Tesla, and around 100 other companies signed legal documents on Monday opposing President Donald Trump's immigration ban.

But Bloomberg reports that there's one tech giant in particular that has taken the lead in co-ordinating the funding for the amicus brief — a legal document signed by parties that have an interest in a case but are not a part of the litigation.

Alphabet, Google's parent company, is spearheading the funding efforts, according to Bloomberg sources who claim to have knowledge of the arrangement.

The Mountain View firm is reportedly working with Washington D.C. law firm Mayer Brown on the amicus brief.

Other firms have reportedly offered to chip in on the legal costs and Alphabet plans to accept their offers, sources told Bloomberg.

Trump's executive order on immigration bars citizens of seven Muslim-majority countries from entering the US for at least 90 days. The countries affected are Iran, Iraq, Libya, Somalia, Sudan, Syria, and Yemen. A federal judge issued a temporary nationwide hold on the ban Friday night.

Google has set up a $4 million (£3 million) fund of its own to support its immigrant employees around the world. The search-engine giant is pledging $2 million (£1.6 million) of its own money, while the remaining $2 million (£1.6 million) is expected to be made up in donations from Googlers.

"We're concerned about the impact of this order and any proposals that could impose restrictions on Googlers and their families, or that could create barriers to bringing great talent to the US," Google said in a statement seen by USA Today. "We'll continue to make our views on these issues known to leaders in Washington and elsewhere."

The executive order affects at least 187 Google employees, according to Google CEO Sundar Pichai.

Alphabet reportedly declined to comment on the Bloomberg story and did not immediately respond to Business Insider.