An access panel for a horizontal opening, the access panel (11) comprises a parallel array (12) of members (14, 15, 16) and a lateral extent (W) of the array (12) corresponding to a lateral extend (D) of the opening between first (17) and second (18) end members of the array (12) defining a length (L) of the panel (12). At least two pantograph units (20, 21) extend between the first (17) and second (18) end members and each member (14-16, etc.) in the parallel array (12) is pivotably linked to each pantograph unit. The members (14, 15, 16 etc) and units (20, 21) permit the panel (11) to function as a planar structure and enable the length (L) of the panel (11) to be varied between a minimum length (L1) and a maximum length (L2) and an intermediate configuration having a length between the minimum and maximum lengths (L1, L2).