Foundation for positioning an elongate structure, such as a lamppost, in an vertical direction, said foundation comprising: - a receiving element comprising a receiving opening, wherein said receiving element defines a receiving space extending in a longitudinal direction for receiving, via said receiving opening of said receiving element, a lower part of said elongate structure; - a flange attached to said receiving element; - a compression element provided with a first through hole for allowing said elongate structure to pass said compression element via said first through hole; - two positioning elements (9, 11) having, respectively, a second through hole and a third through hole for allowing said elongate structure to pass each of said two positioning elements (9, 11) via said corresponding second through hole and said third through hole, wherein said two positioning elements (9, 11) are arranged to be provided between said flange and said compression element, characterized in that the foundation comprises: - a deformable plate element provided with a fourth through hole for allowing said elongate structure to pass said deformable plate element via said fourth through hole, wherein said deformable plate element is arranged to be provided between said two positioning elements (9, 11) and wherein said two positioning elements (9, 11) and said deformable plate element are displaceable relative to said receiving element, said flange and said compression element in a virtual plane perpendicular to said longitudinal direction for, in use, positioning said elongate structure in said vertical direction; - a compression arrangement arranged for compressing said deformable plate element between said two positioning elements (9, 11), via said flange and said compression element, such that said deformable plate element is deformed and urged against said elongate structure for fixating said elongate structure relative to said receiving element in said vertical direction. - a receiving element comprising a receiving opening, wherein said receiving element defines a receiving space extending in a longitudinal direction for receiving, via said receiving opening of said receiving element, a lower part of said elongate structure; - a flange attached to said receiving element; - a compression element provided with a first through hole for allowing said elongate structure to pass said compression element via said first through hole; - two positioning elements (9, 11) having, respectively, a second through hole and a third through hole for allowing said elongate structure to pass each of said two positioning elements (9, 11) via said corresponding second through hole and said third through hole, wherein said two positioning elements (9, 11) are arranged to be provided between said flange and said compression element, - a deformable plate element provided with a fourth through hole for allowing said elongate structure to pass said deformable plate element via said fourth through hole, wherein said deformable plate element is arranged to be provided between said two positioning elements (9, 11) and wherein said two positioning elements (9, 11) and said deformable plate element are displaceable relative to said receiving element, said flange and said compression element in a virtual plane perpendicular to said longitudinal direction for, in use, positioning said elongate structure in said vertical direction; - a compression arrangement arranged for compressing said deformable plate element between said two positioning elements (9, 11), via said flange and said compression element, such that said deformable plate element is deformed and urged against said elongate structure for fixating said elongate structure relative to said receiving element in said vertical direction.