Let H be a subgroup of the fundamental group π 1 (X, x 0 ). By extending the concept of strong SLT space to a relative version with respect to H, strong H-SLT space, first, we investigate the existence of a covering map for strong H-SLT spaces. Moreover, we show that a semicovering map is a covering map in the presence of strong H-SLT property. Second, we present conditions under which the whisker topology agrees with the lasso topology on X H . Also, we study the relationship between open subsets of π wh 1 (X, x 0 ) and π l 1 (X, x 0 ). Finally, we give some examples to justify the definition and study of strong H-SLT spaces.