Influential cadres within Tanzania's ruling Chama Cha Mapinduzi party are fighting against allegations of plotting to block President John Magufuli from seeking a second term in 2020.
Former CCM secretaries-general Abrahman Kinana and Yusuf Makamba last week issued a letter alleging a plot by powerful people in government seeking to frame former CCM and government leaders for treason.
The letter has attracted counteraccusations from President Magufuli's loyalists who stand by their claims.
The president's supporters accuse former party leaders, including the authors of the letter, of ganging up to undermine the party and go against its tradition of allowing two terms in office for the presidency.
Should it come to pass, it will be the first time that a sitting president under CCM is challenged from within the party before two full terms.
While the matter has largely been debated in whispers, the letter by Mr Kinana and Mr Makamba has brought the discussions to the fore, with those who back the president terming the two former officials as "hirelings" of the anti-Magufuli plotters.
Mr Makamba and Mr Kinana served as CCM secretaries-general between 2009 and 2011 and 2012 and 2018 respectively. They remain influential in CCM circles and command respect across the political divide.
Their letter was addressed to CCM's Advisory Council, comprising former presidents and retired top party officials.
They demanded action by the Council on what they said was inaction by both the party and government leaders against Cyprian Musiba, who owns Fahari Yetu and Tanzanite newspapers and whom they say has constantly smeared their reputation.
Mr Musiba rose to prominence in 2016 after he established his newspapers in which he published stories targeting several former and current leaders in the private sector, government and CCM.
Mr Kinana and Mr Makamba alleged that Mr Musiba was enjoying protection from people in positions of power.
They said his actions sought to justify a possible plot to trump up treason charges against former and current leaders for a desired political end.
"Mr Musiba is being used to intimidate and silence targeted leaders and agencies. The purpose seems to link certain people with crimes, disciplinary issues and treason," the letter reads.
The secretary to the Elders Council, Pius Msekwa, said he had advised the Council to handle the matter raised in the letter. He said that while the council deliberates on the contents of the letter, they have no powers outside CCM's party machinery to act.
"CCM's constitution doesn't give the council powers to make decisions outside its jurisdiction, especially on day-to-day running of the party. This responsibility is with those holding leadership positions," said Mr Msekwa.
He added that those who have been targeted by Mr Musiba should defend themselves against such attacks.
Former foreign affairs minister Bernard Membe, who has been accused by a section of CCM members of being behind the team plotting against President Magufuli, has sued Mr Musiba over stories he has published against him.
Nzega Urban MP, Hussein Bashe, called a hurried press conference last week on Wednesday, to castigate Mr Kinana and Mr Makamba for writing the letter and publicly releasing it.
"Mr Kinana and his supporters are seeking to divide the party and undermine President Magufuli's vie for a second term. Mr Kinana knows that what he did is against our constitution as the Elders Council isn't constitutionally mandated to handle such matters," said Mr Bashe who does not shy away from criticising the government in parliament.
"They are only seeking to undermine President Magufuli and weaken the party ahead of the forthcoming elections," he added, warning that the move was unacceptable.
It is understood that Mr Bashe has his own share of problems with President Magufuli's inner circle due to his outspoken nature and his quick dismissal of the letter was seen as a bargaining chip.
Mr Bashe would also not support Mr Kinana and Mr Makamba whom he views as rivals in the party.
The Nzega Urban MP supported former premier Edward Lowassa during the nomination race for the CCM ticket in the 2015 general election. However, Mr Lowassa defected to the opposition after he was locked out of CCM.
During his press conference, Mr Bashe suggested that a former president was among retired top officials who were consulted by Mr Kinana and Mr Makamba before writing the letter.
Political commenters say the ongoing public spat could reawaken bitter rivalries between politicians linked to former president Jakaya Kikwete and Mr Kinana, and those linked with President Magufuli and Mr Lowassa ahead of next year's general election.
Inspector General of Police Simon Sirro said his officers are under instruction to attend and monitor all meetings held by political parties, religious institution and other organisation after detecting ill motives.
A tweet purportedly from the IGP's account, which was circulating on social media last week said, "There is a need to deploy police squad to Chadema meetings. The aim is to know everything discussed therein so as to save our country from terrorism because there are indications of ill motives."
Speaking to The EastAfrican, IGP Sirro said he did not mean to single out Chadema because his officers will be present in meetings conducted by all political parties and even religious institutions.
Francis Mutungi, Registrar of Political Parties, said matters pertaining to national security are sensitive and the IGP might have reached the decision after being satisfied about the threat level.
Although the police have not singled out opposition parties in the surveillance, it is most likely that the opposition will be most affected.
Since the ban on political party rallies in 2016, the ruling party is known to hold their meetings uninterrupted, but from time to time opposition meetings have been raided by the police.
Last week, police in Bariadi western Tanzania raided the Chadema women leaders meeting and arrested its chairperson.