The phrase "tough negotiations" means that the process of reaching an agreement or making a deal is difficult, challenging, or requiring a lot of effort and skill to achieve a favorable outcome. Full definition
Through tough negotiations with multiple sign backs, purchasers who are serious tend to find out the hard way that sellers are serious too. (remonline.com)
It's claimed that both club and player have been in tough negotiations throughout the season to try and work a new deal but as yet no suitable agreement has been reached. (caughtoffside.com)
How do you approach tough negotiations in both the offer and inspection processes? (rismedia.com)