The United National Party will hold a massive public demonstration at Galle Face green as a show of strength.
Prime Minister Ranil Wickremesinghe and other senior leaders of the party will attend the rally this afternoon.
The rally takes place a day after President Maithripala Sirisena's critical speech targeting the UNP and its leadership after Prime Minister Ranil Wickremesinghe's swearing-in.
The UNP has already announced that hundreds of thousands of party supporters will attend the rally in support of Wickremesinghe and his new government.
"We invite everyone who supported the struggle for democracy to join the public demonstration at Galle Face Green today. Let's leave all differences aside and unite with the aim of strengthening #SriLanka's democracy, " UNP MP Sagala Ratnayaka tweeted this morning.