06/09/2015 08:20 EDT | Updated 06/09/2016 05:59 EDT

Mike Duffy trial: Melanie Mercer, ex-aide, to be cross-examined

Mike Duffy's defence lawyer, Donald Bayne, is back in an Ottawa courtroom today to continue his cross-examination today of the suspended senator's former executive assistant, Melanie Mercer.

​Duffy has pleaded not guilty to 31 charges of fraud, breach of trust and bribery related to expenses he claimed as a senator and later repaid with money from the prime minister's former chief of staff, Nigel Wright. The trial, which began April 7 in the Ontario Court of Justice in Ottawa, is in its 29th day. 

Crown prosecutor Mark Holmes spent much of Monday asking Mercer to review a series of contracts and travel claims of her former boss. In her role as executive assistant, Mercer had filled out the details on some of those forms, based on information provided to her by Duffy or gleaned from his daily diary, she testified. 

But she also testified that Duffy pre-signed a stack of blank travel claims before any details about trips had been provided on the documents.

Mercer said they had a "different process" in their office. She said that Duffy signed the forms before details had been entered, even though, she admitted, he was supposed to sign it after to certify the claims. 

Executive assistants from other Senate offices had suggested to her to have Duffy sign a stack of blank travel claim forms, because "that's what they did in their office to help expedite the process for filing claims," she testified.

Mercer also testified that she wasn't aware of the services being provided to Duffy by a number of individuals who later received cheques for those services through former Duffy associate Gerald Donohue.

Donohue had been awarded a series of Senate research contracts with Duffy worth nearly $65,000 — contracts that Mercer herself had reviewed.

The RCMP has said Donohue received the money for "little or no apparent work." The Crown alleges that pool of money was used by Duffy to pay for a series of expenses. The Crown contends that some of those expenses would not have been covered by the Senate.