A sliding compound mitre saw comprising: a base assembly (102, 104) connected to a mounting portion; a motor unit pivotally connected to a motor support which is mounted on the mounting portion to allow the motor unit to pivot towards or away from the base assembly (102, 104) to perform chop cuts, the motor unit having an output drive spindle upon which a circular saw blade can be rigidly mounted to be rotationally driven by the motor unit; at least one rearward pivotal guard pivotally mounted on the motor unit which can pivot from a first position, where it surrounds at least a portion of the lower edge of a saw blade when mounted on the spindle, to a second retracted position where the portion of the lower edge of the saw blade is exposed; and a pivotal guard actuating mechanism which moves the at least one rearward pivotal guard from its first enclosed position to its second retracted position when the motor unit is pivoted towards the base assembly (102, 104), wherein the guard actuation mechanism comprises a mechanical linkage having two parts, the first part connected to the rearward pivotal guard, the second part connected to the motor support, wherein one part comprises a cam, the other a cam follower, and being arranged so that, as the motor unit is pivoted towards the base assembly (102, 104), the cam follower rides over the cam to pivot the at least one rearward pivotal guard; wherein there is further provided at least one forward pivotal guard (220; 320) pivotally mounted on the motor unit which can pivot from a first position, where it surrounds at least a portion of the lower edge of a saw blade when mounted on the drive spindle, to a second retracted position where the portion of the lower edge of the saw blade is exposed, the pivotal guard actuating mechanism moving the at least one forward pivotal guard (220; 320) from its first position to its second retracted position when it moves the at least one rearward pivotal guard from its first position to its second retracted position as the motor unit is pivoted towards the base assembly (102, 104); characterised in that the mechanical linkage comprises a bar which connects between the motor support and the at least one forward pivotal guard to pivot the at least one forward pivotal guard wherein the cam is formed on the bar and the cam follower is mounted on the rearward pivotal guard; and wherein there is further provided a table mounted on top of the motor unit to enable the saw to act as a table saw. a base assembly (102, 104) connected to a mounting portion; a motor unit pivotally connected to a motor support which is mounted on the mounting portion to allow the motor unit to pivot towards or away from the base assembly (102, 104) to perform chop cuts, the motor unit having an output drive spindle upon which a circular saw blade can be rigidly mounted to be rotationally driven by the motor unit; at least one rearward pivotal guard pivotally mounted on the motor unit which can pivot from a first position, where it surrounds at least a portion of the lower edge of a saw blade when mounted on the spindle, to a second retracted position where the portion of the lower edge of the saw blade is exposed; and a pivotal guard actuating mechanism which moves the at least one rearward pivotal guard from its first enclosed position to its second retracted position when the motor unit is pivoted towards the base assembly (102, 104), wherein the guard actuation mechanism comprises a mechanical linkage having two parts, the first part connected to the rearward pivotal guard, the second part connected to the motor support, wherein one part comprises a cam, the other a cam follower, and being arranged so that, as the motor unit is pivoted towards the base assembly (102, 104), the cam follower rides over the cam to pivot the at least one rearward pivotal guard; wherein there is further provided at least one forward pivotal guard (220; 320) pivotally mounted on the motor unit which can pivot from a first position, where it surrounds at least a portion of the lower edge of a saw blade when mounted on the drive spindle, to a second retracted position where the portion of the lower edge of the saw blade is exposed, the pivotal guard actuating mechanism moving the at least one forward pivotal guard (220; 320) from its first position to its second retracted position when it moves the at least one rearward pivotal guard from its first position to its second retracted position as the motor unit is pivoted towards the base assembly (102, 104); characterised in that the mechanical linkage comprises a bar which connects between the motor support and the at least one forward pivotal guard to pivot the at least one forward pivotal guard wherein the cam is formed on the bar and the cam follower is mounted on the rearward pivotal guard; and wherein there is further provided a table mounted on top of the motor unit to enable the saw to act as a table saw.