DAR ES SALAAM (Reuters) - A senior Tanzanian politician quit the ruling party on Monday complaining of human rights abuses and a weakening of democracy in the east African nation, in a move political analysts said could trigger a wave of defections to opposition parties. Since taking office in late 2015, President John Magufuli has introduced sweeping reforms, including as an anti-corruption drive that has won him some praise from Western donors. But his administration is also increasingly being accused by his opponents of undermining democracy by curbing dissent and stifling free speech, including banning newspapers. On Monday, Lazaro Nyalandu, who once served as a cabinet minister and has been a member of parliament for the ruling Chama Cha Mapinduzi (CCM) party for 17 years, said he was  deeply concerned  by human rights abuses and the direction of the economy.  It is evident that CCM has lost its way judging from the current political climate, leadership and economic trajectory in Tanzania,  Nyalandu said in a statement.  I have decided to resign from my position as a member of the CCM national executive committee and all other leadership positions in the party effective from today.  Nyalandu said he had also submitted his resignation as a member of parliament. The veteran politician was among more than a dozen candidates who sought the ruling party s presidential nomination in 2015 but was defeated by Magufuli. Bashiru Ally, a Dar es Salaam-based political analyst, said Magufuli s reforms could prompt further defections from the ruling party but said the opposition was poorly placed to benefit from such a trend.  Opposition parties are overly dependent on personalities who defect from CCM,  he told Reuters.  (But) they can only make temporary gains from such defections. They are not institutionalised and lack mass grassroots mobilization strategies.  CCM, which has been in power since Tanzania gained independence from Britain in 1961, has seen its support among young urban voters decline in previous elections, but opposition parties are too fragmented to oust it from power, analysts said. 