The Lawn Tennis Association has been fined £820,000 by the ATP for banning Russian and Belarusian male players from this summer's grass-court events.
The ban was imposed in reaction to Russia's invasion of Ukraine.
The governing body has also been warned it could lose its ATP membership if a similar decision is made next year.
The LTA says it is "deeply disappointed" and has accused the ATP of showing a "surprising lack of empathy for the situation in Ukraine."
The punishment follows six-figure fines for the LTA and the All England Lawn Tennis Club, who organise Wimbledon, from the WTA for excluding female Russian and Belarusian players.
The ATP, which oversees men's tennis events outside of the Grand Slams, allows Russians and Belarusians to compete in Tour events but not under their national flags.
"The ATP, in its finding, has shown no recognition of the exceptional circumstances created by Russia's invasion of Ukraine, or the international sporting community and UK Government's response to that invasion," the LTA said in a statement.
"The ATP appear to regard this matter as a straightforward breach of their rules - with a surprising lack of empathy shown for the situation in Ukraine, and a clear lack of understanding of the unique circumstances the LTA faced."
The LTA has been fined $200,000 (£164,018) for each of the five ATP events it staged this year: the tour level events at The Queen's Club and Eastbourne, and the Challenger tournaments at Surbiton, Nottingham and Ilkley.
The LTA followed the All England Club's (AELTC) lead when it decided to ban all Russian and Belarusian players from Wimbledon, following government pressure.
On Wednesday, Thomas Bach - president of the International Olympic Committee (IOC) - said he disagreed with the decision by Wimbledon and the LTA to ban Russian and Belarusian players, saying: "Governments should not decide the grounds on who participates in which sports events. [It] should be on sporting merits, not on political interference."
The women's WTA Tour has already fined the LTA $750,000 (£615,067) for excluding the players from its grass court events in Nottingham, Birmingham and Eastbourne.
The LTA's strongly worded statement continued with a warning that the fine will affect future tournaments being staged in the UK.
"The financial impact of both this fine and the WTA's fine will have a material impact on the LTA's ability to develop and host tennis in this country," it continued.
"For example, we had intended to host a number of ATP Challenger level events to give more opportunities to lower ranked players in the first quarter of 2023 and will now not be able to do this, particularly given the possibility of further fines.
"We will carefully consider our response and we await the outcome of our appeal against the WTA's decision and sanction."
Both the ATP and the WTA stripped Wimbledon of ranking points this year, and it has not been lost on the LTA that points will be awarded at this month's United Cup - despite Russian players being excluded.
The ATP will donate the fine to humanitarian relief in Ukraine.
Another very sensitive decision awaits the AELTC and the LTA in the spring. With no end to the war in Ukraine in sight, the two organisations will have to decide whether they are prepared to incur the wrath of governing bodies and some players by banning Russians and Belarusians once again.
Secretary of State for Digital, Culture, Media and Sport Michelle Donelan said: "Despite widespread condemnation, the international tennis tours are determined to be outcasts in this, with investment in the growth of our domestic game hampered as a result.
"This is the wrong move by the ATP and WTA. I urge them to think carefully about the message this sends, and to reconsider."