While BN is expected to win the twin by-elections, questions remain over the margin of victory the ruling party can clinch.
NGO Kuasa chief executive Praba Ganesan predicted that BN could win Kuala Kangsar with more than 50 percent of the votes, but not in Sungai Besar.
He said this was largely because the two constituencies had different levels of economic growth.
Praba said Kuala Kangsar voters were more inclined to support BN due to the federal government's distribution of goodies, since the royal town's development was lagging.
According to Praba, BN has granted full university status to Kolej Universiti Islam Sultan Azlan Shah and also promised to allocate RM49 million for Kuala Kangsar flood mitigation projects.
“As (BN government) makes promises (to develop) Kuala Kangsar, we feel that BN candidate Mastura Mohd Yazid will win.
“She might be able to gain more than 50% of the vote,” he told a press conference in Kuala Lumpur this afternoon.
However, Sungai Besar was a different story as the area was more economically developed than Kuala Kangsar, Praba said.
Praba highlighted the Pakatan Harapan-led Selangor government's positive track record and DAP Sekinchan state assemblyperson Ng Suee Lim's favourable image.
Sekinchan is one of the two state seats under Sungai Besar.
“The goodies effect from federal government is far less compelling (in Sungai Besar) which it is economically striving.
“If this was a straight fight, the BN candidate (Budiman Mohd Zohdi) will be struggling as Umno's fortune in the state has been dwindling... if he wins, the BN candidate might garner 45% or less of the votes.”