He also slammed the Raman Singh-led BJP government in Chattisgarh for failing to curb naxalism, stressing that the fruits of development have not reached the areas where the writ of the naxals runs large.
Singh also attacked the state government for failing to provide sufficient security to Congress leaders who were killed in a massive naxal attack in May this year.
"We should criticise the opposition parties and their policies with which we do not agree. But in this regard, we have to distinguish ourselves, especially from the BJP some of whose leaders use bad language against other party leaders and Chief Ministers," Singh said without naming anyone.
He said Congress workers should refrain from using words which are "insulting" and are against the "dignity " of the party.
Addressing party workers at an indoor stadium here, Singh said it was legitimate for political parties to aim to come to power.
"But to achieve the goal, no party should follow the route of cheap publicity...elections to the state assemblies and the general elections are nearing. Keeping this in mind opposition parties are making various claims. Some senior opposition leaders are saying things which are not based on facts," Singh said.
He also said that on many occasions, "over-excited BJP leaders change history and geography of the country."
"The people of Chhattisgarh and India are aware that parties that talk big are not capable of coming to power...we should alert the people about parties who have communal ideology but are talking about secularism to mislead people," he said.
Slamming the Chhattisgarh government for the attack on Congress leaders by Maoists, the Prime Minister said such incidents reflect the law-and-order situation in the state.
"The Jhiramghati incident reflects the bad law-and-order situation in the state. Providing security to people is one of the primary responsibilities of any state. BJP government of Chhattisgarh has totally failed to fulfill its responsibilities," he said.
"They (the Chhattisgarh government) say after the May 25 incident they were sensitive towards the happenings. But what they don't say is that there were serious security lapses due to which Congress leaders and security personnel lost their lives. They do not say that security was not provided to Congress leaders because of political differences," he said.
Singh slammed the state government for high infant mortality and maternal mortality rates. He also said that the BJP praises the Public Distribution System of the Chhattisgarh government, but fails to mention that 90 per cent of subsidy comes from the central government.
He said that the Centre has planned several projects for Chhattisgarh but they cannot be implemented because of non-cooperation from the state government. He added that Centre has planned IIT and AIIMS hospital, which is to come in Raipur.
He also said that 24 big projects have been planned for Chhattisgarh. These include four projects Dipka and Gevoz Coal expansion projects, Bhilai Steel Power Plant Project and NTPC's Super Thermal Power Project, costing Rs 33,000 crore.
Prime Minister also said that special assistance has been extended to 14 Naxal-affected districts of the state.
Singh also highlighted the achievements of the UPA government and compared it with the 6-year rule of the BJP-led NDA.
"The economy grew at 5.4 per cent during the NDA rule, but it grew by 8 per cent during the UPA rule. Per capita income increased by 3.7 per cent during the NDA regime, but under UPA it grew by 6.5 per cent. Between 2004 and 2009, poverty declined three times than the last ten years," he said.
Singh said rural areas and small towns have prospered since last 9 years and states that were once considered as backward have seen rapid development.
"Agricultural produce has increased and we are the largest exporter of rice. The increase in the production has enabled us to come with the Food Security Bill. Because of this Chhattisgarh will also receive food grains at much cheaper rate than before," he said.
Singh said the country has also made progress in infrastructure and power sector and that electricity production has shown a rise in the last 9 years. The rise was more than what was seen in all the years after independence.
"In last 9 years, NHAI constructed 17,000 km of road, of which 2 lakh were in rural areas. To ensure that farmers are not affected after acquisition of land due to such projects, we came up with Land Acquisition Bill," Manmohan Singh told the gathering.