David Davis claimed victory in the Haltemprice and Howden by-election - but on a lower turnout and by fewer votes than at the last general election.
The former shadow home secretary easily defeated, by a majority of 15,355, the motley assortment of 25 candidates standing against him.
But his 17,113 vote count was smaller than the 22,792 he polled at the 2005 election.
Turnout in the East Yorkshire constituency was down to just over 34 per cent in yesterday's by-election, compared to 70.2 per cent three years ago.
Mr Davis resigned the seat last month to seek re-election on a civil liberties platform after 42-day pre-charge detention for terror suspects was approved by the Commons.
Neither Labour nor the Liberal Democrats - who came second in Haltemprice and Howden in 2005 - took part in yesterday's by-election.
Speaking after the declaration, Mr Davis said his victory had been a "shot across the bows of Gordon Brown's arrogant, arbitrary and authoritarian Government".
"Today the people of Haltemprice and Howden have delivered a stunning - a stunning - message to the Government, and our campaign has reverberated across the country," he said.
"Four weeks ago as Gordon Brown stooped into the gutter to rig the vote on 42 days, ministers crowed that 69 per cent of people voted 42 days.
"Today just 36 per cent supported it.
"Four weeks ago the Government touted public support for a range of other draconian measures.
"Today 71 per cent support my stand against the attacks on British liberty."
He said that after Baroness Manningham-Buller, the former head of MI5, "savaged" 42 days earlier this week, the proposal now "lies in tatters, robbed of any remaining credibility".
Mr Davis said his re-election was only the beginning of his campaign as he takes up his Commons seat again on Monday.
"I do so with a clear mandate, to fight Gordon Brown's vision of Big Brother Britain tooth and nail, to stop 42 days in its tracks, to prevent the disaster of ID cards before it happens, to protect our personal privacy from being ransacked by the ever-intrusive state," he added.
"But most of all for the thousands upon thousands that have written to me, supported me, and voted for me, I return to fight for those fundamental freedoms that define our way of life - freedoms that millions died defending, freedoms that make Britain great."
Some 23 candidates lost their £500 deposits after failing to poll 5 per cent of the vote.
Only Mr Davis, the Greens' Shan Oakes and the English Democrats' Joanne Robinson kept their deposits.
The announcement was delayed after Ms Robinson, finishing 44 votes behind the Green candidate, forced a recount.
Earlier in the evening, Mr Davis made clear that he did not expect to return to the shadow cabinet.
"I've already discounted all of that," he said. "I took on board that I would lose my shadow cabinet post and probably my shadow cabinet future. I accept that."
Home Office Minister Tony McNulty repeated Labour's claim that Liberal Democrat leader Nick Clegg had done a deal with Mr Davis that the Lib Dems would not challenge him.
"This by-election was a vain stunt that became and remains a farce," he said.
"Labour never believed a parliamentary by-election should be held at taxpayers' expense to resolve tensions at the top of the Conservative Party."
HALTEMPRICE & HOWDEN
*David Davis (C) 17,113 (71.57 per cent, +24.11 per cent)
Shan Oakes (Green) 1,758 (7.35 per cent)
Joanne Robinson (Eng Dem) 1,714 (7.17 per cent)
Tess Culnane (NF) 544 (2.28 per cent)
Gemma Garrett (Miss GB Party) 521 (2.18 per cent)
Jill Saward (Ind) 492 (2.06 per cent)
Mad Cow-Girl (Loony) 412 (1.72 per cent)
Walter Sweeney (Ind) 238 (1.00 per cent)
John Nicholson (Ind) 162 (0.68 per cent)
David Craig (Ind) 135 (0.56 per cent)
David Pinder (New Party) 135 (0.56 per cent)
David Icke (ND) 110 (0.46 per cent)
Hamish Howitt (Freedom) 91 (0.38 per cent)
Christopher Talbot (SEP) 84 (0.35 per cent)
Grace Astley (Ind) 77 (0.32 per cent)
George Hargreaves (Ch P) 76 (0.32 per cent)
David Bishop (Elvis) 44 (0.18 per cent)
John Upex (Ind) 38 (0.16 per cent)
Greg Wood (Ind) 32 (0.13 per cent)
Eamonn Fitzpatrick (Ind) 31 (0.13 per cent)
Ronnie Carroll (History) 29 (0.12 per cent)
Thomas Darwood (Ind) 25 (0.10 per cent)
Christopher Foren (Ind) 23 (0.10 per cent)
Herbert Crossman (Ind) 11 (0.05 per cent)
Tony Farnon (Ind) 8 (0.03 per cent)
Norman Scarth (Ind) 8 (0.03 per cent)
C maj 15,355 (64.22 per cent)
Electorate 70,266; Turnout 23,911 (34.03 per cent, -36.12 per cent)
2005: C maj 5,116 (10.65 per cent) - Turnout 48,029 (70.15 per cent). Davis (C) 22,792 (47.45 per cent); Neal (LD) 17,676 (36.80 per cent); Hart (Lab) 6,104 (12.71 per cent); Mainprize (BNP) 798 (1.66 per cent); Lane (UKIP) 659 (1.37 per cent)Reuse content