Washington (CNN) President Donald Trump has rapidly increased his campaign spending in recent months, pouring big sums into massive rallies and legal bills as he stumps for imperiled congressional Republicans and confronts inquiries about Russia's interference in the 2016 election.

Trump's campaign committee spent $7.7 million between July 1 and September 30, more than double its spending during the previous quarter.

Its legal expenses also soared in that time, accounting for $1.6 million, or about one-fifth of his campaign's total costs during the three-month period. That's the most his campaign has spent on legal bills in any quarter.

About $1.3 million of that total went to Jones Day, the firm that handles the campaign's election matters but also has represented it in connection with the investigations into Russia's election meddling.

A campaign spokesman did not respond Tuesday to an inquiry about the growing legal expenses.