Tories snatched a Sunderland seat from Labour in the latest council by-elections, sending a warning to Gordon Brown as he ponders whether to call a general election.
With all nine results in from yesterday's contests, Conservatives have snatched back a projected 4.6% nationwide lead compared with last week's 1.4% deficit.
Labour gained from independent at Mansfield, Nottinghamshire, and held six seats but on the basis of results at Portsmouth and Northamptonshire, Tories would look on course for a sweeping parliamentary victory at Portsmouth North and a closer one at Corby in any early poll.
At Dover the 5.5% swing in a Kent County Council contest for Dover Town - which covers more than a quarter of the Commons constituency's electorate - would be enough for Conservatives to take it.
But the outcome in the district's Aylesham ward produced one of only two major swings to Labour.
In a further boost to the battered morale of David Cameron's Tories ahead of their conference next week, they successfully defended control of Cheshire County Council.
At Sunderland Tory Angela Cuthbert gained a Washington East seat on a 3.7% swing.
Labour's John Smart won from the Mansfield Independent Forum at Lindhurst with Conservatives trailing in fourth place.
Tories leapt into second place at Portsmouth's Nelson ward - just 109 votes behind Labour.
There was no swing between the two major parties since May when Conservatives had a lead of more than 20% in votes cast in the Portsmouth North constituency.
Analysis of 23 comparable results over September gives a 2.3% Tory lead.
A calculation based on 17 contests fought both times by the three leading parties gives a line-up of: C 38.6%. Lab 32.9%, Lib Dem 21.5%.
Cheshire County - Gowy: C 1863, Lib Dem 1419, Lab 307, Ukip 107. (May 2005 - C 3936, Lib Dem 2666, Lab 1555). C hold. Swing 1.8% C to Lib Dem.
Chester-le-Street District - Chester Central: Lab 324, C 89, Lib Dem 81, BNP 51. (May 2007 - Two seats Lab 411, 389, C 172). Lab hold. Swing 1.6% C to Lab.
Dover District - Aylsham: Lab 661, C 108, Ind 59, No description 1. (May 2007 - Two seats Lab 831, 808, C 311, 287, No description 75). Lab hold. Swing 11.6% C to Lab.
Dover District - Maxton, Elms Vale and Priory: Lab 365, Lib Dem 274, C 252, Ind 70, Ukip 65, Ind 56. (May 2007 - Three seats Lab 733, 647, C 624, Lab 602, C 566, 545, Lib Dem 381, 296, 291, Ind 243). Lab hold. Swing 5.1% Lab to Lib Dem.
Kent County - Dover Town: Lab 1860, C 1348, Lib Dem 420, Ind 300, Ukip 256. (May 2005 - Two seats Lab 6194, 5888, 3455, 3122, Lib Dem 2658, 2255). Lab hold. Swing 5.5% Lab to C.
Mansfield District - Lindhurst: Lab 339, Ind 302, Lib Dem 215, C 61, Green 35 . (May 2007 - Two seats Ind 559, 449, Lab 392, 313, C 266, 186, Green 136). Lab gain from Ind. Swing 9.4% C to Lab.
Northamptonshire County - Lloyds: Lab 1093, C 375, Lib Dem 311, BNP 265. (May 2005 - Lab 2620, C 886, Lib Dem 707). Lab hold. Swing 3% Lab to C.
Portsmouth City - Nelson: Lab 791, C 682, Lib Dem 548, Ukip 90, Green 78, English Democrats 71 . (May 2007 - Lab 840, Lib Dem 717, C 711, English Democrats 199, Green 168). Lab hold. Swing 0.0% C to Lab.
Sunderland Borough - Washington East: C 1196, Lab 994, Lib Dem 206 . (May 2007 - C 1245, Lab 1220, Lib Dem 441, BNP 195). C gain from Lab. Swing 3.7% Lab to C.Reuse content