Prime Minister Manmohan Singh [Images] on Thursday said the office of Lok Sabha Speaker has been "truly elevated and dignified" by Somnath Chatterjee [Images], who set himself as a "role model".

"We strained your patience and at times, even your conscience. There were unusual times in which you had to take a call between defending parliamentary propriety and heeding to the demands of the organisation that you had spent a lifetime building," he said.

The Prime Minister's brief statement was read out by Leader of the Lok Sabha Pranab Mukherjee [Images] on the last day of the last session of 14th Lok Sabha, which adjourned sine die.

Noting that on such occasions "your sagacity prevailed", he said he had no words to express the gratitude of the House for upholding the dignity of both the high office and the institution "in times of personal trial".

"History will be the best judge of your unique contribution. You stood like a rock to defend our best Parliamentary traditions and in doing so have raised the bar for those to follow," he said.

The prime minister said he would be failing in his duty if he did not thank Leader of the Opposition L K Advani [Images] for "always being constructive as we collectively addressed national challenges inspite of occasional disagreements".