The former security chief, who was expelled from Fatah in 2011 and now lives in the United Arab Emirates, has not been in court for any of the hearings in the West Bank city of Ramallah.
According to his legal team, the 53-year-old is on trial in connection with the alleged misuse of $17 million (15 million euros) in expenses.
On Thursday, Palestinian police raided the offices of two Fatah parliament members, Majid Abu Shammaleh and Alaa Addin Yaghi, who left the Gaza Strip along with Dahlan in 2007 after Hamas seized the enclave.
"Their associates were placed in detention and their computers and a number of documents were seized illegally," Dahlan's lawyer Sevag Torossian said in a statement, referring to the two.
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Palestinian reports said the two parliamentarians said they were not arrested because of their immunity, a privilege lost by Dahlan after his expulsion from Fatah in 2011 following the graft allegations.
Torossian denounced what he called a "policy of using the judiciary for political means", and accused Abbas of "exploiting the courts like toys, for purely political ends".
"Palestine signed the 1966 International Covenant on Civil and Political Rights" which guarantees the right to a fair trial, he said.
Torossian added that he would ask European authorities to "address the covenant's violations, as well as the European Parliament and donors who cannot finance or support such private justice".
Once considered a US protege, Dahlan fell from grace in June 2007 after the humiliating rout of his forces from Gaza by the Islamist Hamas during days of deadly street battles.
He has been a bitter Abbas rival ever since, and in May was sentenced in absentia to two years in jail for defamation.